Difference between revisions of "Sonic Adventure AutoDemo"

From Sonic Retro

(Act 3)
(Why the adventure fields send you to the title screen.)
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===Adventure Fields===
===Adventure Fields===
* Only the Egg Carrier and the Casino area of Station Square can load in the proper objects and textures in-game, because they are the only areas that are used in the Autodemo's cutscenes. The other areas are in the game but are missing objects and textures, and will crash or will send the player back to the title screen if accessed in-game.
* Only the Egg Carrier and the Casino area of Station Square can load in the proper objects and textures in-game, because they are the only areas that are used in the Autodemo's cutscenes. The other areas are in the game but are missing objects and textures, and will crash or will send the player back to the title screen if accessed in-game.
* The reason why is 8C768B38 (2C768B38 for Demul) is set to 5, to prevent it, set it to 4 in Cheat Engine.
====Station Square====
====Station Square====
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* The rightmost cell is missing Big's lure upgrade.
* The rightmost cell is missing Big's lure upgrade.
* The fans below the floor spin more slowly.
* The fans below the floor spin more slowly.

Revision as of 05:08, 6 November 2018


SA 98 AutoDemo Title.png
Sonic Adventure AutoDemo
System(s): Sega Dreamcast
Genre: Action

Sonic Adventure AutoDemo is a Sega Dreamcast disc demonstrating the then-upcoming Sonic Adventure. It was released in small quantities, presumably for Japanese retailers and events to help promote the game - it was never released commercially, nor was it seen outside of Japan.

The AutoDemo cycles through various in-game cutscenes (exclusively in the Japanese voice track) on a loop. It is not playable, but much like the final version of the game the cutscenes are rendered in real time by the Dreamcast hardware. The disc has an internal build date of October 16, 1998, putting it roughly 55 days after Sonic Adventure's unveiling at the Tokyo International Forum (in August 22, 1998) and roughly 49 days before the build date of the game's first release in Japan (December 10, 1998). The disc was dumped and released to the general public on May 21, 2013.

With the aid of hacking, it is possible to break the cycle of cutscenes in the AutoDemo and access a fully-fledged prototype version of Sonic Adventure. Though much of the game is complete, with certain stages (Windy Valley) missing in the build despite the date, there are a multitude of differences to the final version as well as left-over content from previous builds.

For whatever reason, the AutoDemo appears to de-synchronize on emulators. If one was to burn the image to a standard CD-R, only Sonic's demo would have synchronization issues.



Sonic Retro emblem.svg Main article: Sonic Adventure AutoDemo/Comparisons

List of Differences

Demo Loop and Game Introduction

  • Because the game is set by default to never take the player's input, the introduction and the demos themselves cannot be skipped.
  • The SEGA logo doesn't appear when first loading the game, but shows up normally before the opening movie if the build manages to loop back to that point.
  • The SEGA logo itself is a darker shade of blue and is much smaller than in the final. It is also missing the "PRESENTED BY" text above it.
  • The introduction has a few differences:
    • Tails has his mouth open when he appears. In the final, it is closed.
    • E-102 Gamma is missing the "102" texturing on the side of his body. This is consistent in all of his appearances in the intro.
  • The list of scenes shown in the autodemo is different than the ones that play in the final game's demo loop:
    • The third demo is the prison scene with Amy and Gamma; usually Knuckles' demo would go here. Because of this omission, Knuckles' theme is unused in this build.
    • The demo positioning for the final demos used for Amy and Gamma are swapped here - Gamma's appears as the fourth and Amy's is the fifth.
    • Gamma's demo has him in Red Mountain instead of Windy Valley (for reasons that will be obvious below).
    • Amy's demo has her in Final Egg instead of Hot Shelter (for reasons that will be obvious below).
    • Big's demo starts in a different part of Emerald Coast.


  • The player starts with 2 lives instead of 4.
  • Dying during the demos does not reset the ring count. This can be seen if the Speed Highway demo is watched with the wonky emulator timings - despite Sonic dying repeatedly his count eventually gets high enough to net him an extra life.
  • The build has an earlier version of the camera system:
    • In practice, it tends to more favor straight-up cuts to new shots in this build than in the final - in the final the camera tends to follow characters and then pan or zoom out as opposed to just cutting.
    • It has more of a tendency to clip through walls and floors.
    • The player-controlled rotation (by pressing either trigger button) is far slower than it is in the final, and has a tendency to invert itself based on the current angle.
  • The HUD has some differences:
    • There is a LEVEL item below the time, which isn't in the final release. As it never has a value next to it whenever the game is hacked to show the HUD in gameplay, it likely had been scrapped by the time of this build.
    • The icon for rings is a different image and is also much larger. This makes the ring count off-center vertically.
    • The contents for TIME are farther to the right than in the final, while the ring count is closer to the left of its icon than in the final.
  • The font for the captions (in Japanese) lacks anti-aliasing during gameplay, such as when hint orbs are encountered.
  • Transitions between acts are broken: the lighting and music will not update for the new act until the player restarts the act or dies.
  • Drowning is not yet properly implemented: the numbers that appear are rather large and only appear for a fraction of a second. There is no drowning animation, and the game will instead just send the player back to the nearest checkpoint.
  • There is no end-level sequence yet - when a character lands on a capsule to end the level, no score tally happens, and the level music doesn't stop. The game will play the Chaos Emerald Get jingle, however.


  • The build has .bins that are compiled at different times - some stages are compiled in September while others are compiled in October. Because of this, several stages won't load because they're pointing at different locations that have been moved or removed in this build's version of 1ST_READ.bin. This basically means that this build is a Frankenstein's monster of stages and assets that were put together from different, previous builds of the game - for instance, Windy Valley is from a build earlier than the Speed Highway included here.
  • An older compressed version of the executable used to play the movies in the demo (MOVIE.PRS) exists in the build, and predates the used, uncompressed version (MOVIE.BIN) by three days, indicating that this change was at the last minute. Both of these files mention the file names of the .SFD videos that can be played, and only MOVIE.BIN actually points to video files that exist in the build. MOVIE.PRS points to SNTM_450.SFD and SAOP600.SFD.
  • The demo's opening movie hsa the final name SAOP1006.SFD, with "1006" being a timestamp. Note that the section above notes that MOVIE.PRS refers to SAOP600.SFD, which would indicate a version of this movie that had a timestamp of 6:00.
  • The SPR Task debug menu seen in the final is present here too, with an additional "ADX" item alongside the items at the bottom left. Of note, ADX is the file extension for audio files.
  • A level select menu is included. It works much like the one in the final, except it uses images to select characters instead of names (but this is broken - the textures do not load in properly). Levels loaded through this menu don't load their textures to RAM properly, and the player cannot control their character without hacking. The menu also shows some differences in the listings:
    • There are three practice levels (PRACTICE 1, PRACTICE 2, PRACTICE 3). In the final, only PRACTICE 1 is listed.
    • Hot Shelter (SHELTER 1, SHELTER 2, SHELTER 3, SHELTER 4) is entirely missing.
    • Knuckles' version of Chaos 6 (CHAOS 6 KN) is entirely missing.
    • The Perfect Chaos slot is just called CHAOS 7 - in the final it is listed as CHAOS 7 1 (despite there being only one CHAOS 7 listing in the final).
    • Egg Walker (EGGMOBILE 2) is entirely missing.
    • The first battle with E-101 (E101) is entirely missing.
    • The Mystic Ruins listings have placeholder names - in this build they are listed as MR A, MR B, MR C, and MR D. In the final, they are MR STATION, MR ISLAND, MR JUNGLE, and MR BASE, respectively.
    • Sky Chase has two slots like in the final (SHOOTING1 and SHOOTING2) despite only having one level present (see below).
  • The lighting looks strange in several stages - this is because the build is missing their respective PL_/SL_ (Palette/Source) files that are used by the game's lighting engine (referred to interally as LANTERN). As a result, the lighting in this levels makes it so that everything lacks shine or shadows. In the case of models that are just one color (like the fire-spewing skulls in Red Mountain), they become hard to make out in gameplay.
  • Fog to hide pop-up for long draw distances is missing entirely. This is especially obvious in the first act of Speed Highway (see below).
  • This build's camera system lacks a few of the camera types that the final has. Alongside this, the list of camera types also got shuffled around in development too - for instance, in the final, type 02 is C_FOLLOW, while type 02 in the autodemo is instead MAGONOTE, with C_FOLLOW being type 29.
  • Several of the stages are missing death zones (data set to NULL). These death zones are what tells the game that the player has fallen to their death (bottomless pits and the ocean in Emerald Coast, for instance). This is why in some stages in this build, the player can fall and just end up in the bottom of the level instead of dying and respawning. Oddly, a few of the stages in question that act like this are ones that are actually properly included in this build, such as Emerald Coast.
  • On hardware, the game can only be played with AV output - trying to play it on scart output will give the audio but not the picture.
  • KEY0502OO.BIN is a demo key file, used in the build's demo playback. However, it is unused - the build instead uses KEY0502. KEY0502OO has a datestamp of Oct 2nd 1998, while the used KEY0502 has a datestamp of Oct 8th 1998. How it differs from the newer, used one is still unknown due to the build's tendency to desynchronize in emulators.
  • There are several mission files (the files detailing the goal of the level) that are made exclusively for this demo, and all of them have localized counterparts. The localized files have some form of "US" or "USA" in their file name (for instance, for instance, MISSION_A_US0.PVR vs MISSION_A0.PVR, outlining the goal of Amy's demo level). All characters have two mission files and two localized counterparts included. The majority of the mission cards are less wide than their final versions, and also have a different set of translations. Of note, E-102's mission card, like with his TGS assets, show that E-104 Epsilon is using the same textures as Gamma.

TGS Mode

  • Editing the value of the menu ID byte allows for the loading of TGS mode - what is left of the game's demo from the Tokyo Game Show 1998.
  • The TGS mode starts with a character menu that uses the 2D character portraits seen in the game's promotional material. The menu header says "Choose Your Buddy!", which also happens to be the name of the character select theme in the official OST release (Sonic Adventure Digi-log Conversion).
  • Choosing any character works as it should: tutorial screens appear and fully-functional levels load that can be played.
  • All characters have localized "How to Play" assets - screens detailing the controls and base objectives for each character.
  • Knuckles has a fully-functioning in-level tutorial, in which the level (Red Mountain) starts with messages at the top and bottom of the screen and an invisible barrier Knuckles needs to glide into to proceed. stg00.bin (see below) still has tutorial strings for Sonic, which indicates that other characters had in-level tutorials as well that were taken out by the time of this build.
    • Both K_TUTORIAL.PRS (the original JP tutorial files, which exist in the JP final but are unused) and K_TUTORIAL_USA.PRS (which are the English-translated tutorial files) are present in this build. K_TUTORIAL_USA is exclusive to this build, and is also fascinating due to its timing - this build predates the formation of Sonic Team USA's localization arm, so whoever translated this is a mystery.

General Sound

  • The game's title screen has a five-second rendition of Open Your Heart. (28.ADX)
  • The 1-up jingle is the Get Chaos Emerald jingle taken straight from Sonic 2. In the final it is a reorchestrated arrangement of that jingle.
  • No voice clips are played when the player finishes a level.
  • The "animal get" sound is present, but unused. Instead, the ring sound is played when an animal is acquired from a Badnik.
  • The classic "bubble collect" sound from the original 2D games is present, but unused. In both this build and the final, no sound is played when a bubble is collected.
  • Likewise, the classic drowning sound from the original 2D games is present, but unused. In the final, voice acting is used for the drowning death animation.
  • The classic sound effect for losing a shield from the original 2D games is present, but unused. In the final, no sound is made in this situation.
  • The classic sound effect for getting hurt is present, but unused. The final uses a modern version of the ring drop sound instead.
  • ALIFE Bank 1, where the Chao voices are stored, has some voices for actions the Chao can't do in this build.
  • Many enemies are missing their sound effects; for instance, the shuffling sound Ice Balls make in Icecap.
  • Tikal's "This Way!" hint (mainly seen in the final in Knuckles' levels) is not voiced in this build.


  • All of the music in this build is in one single file, BGM.AFS. In the final, each song is its own separate file.
  • This build has far many songs in it than are actually used. The following tracks are not loaded in even when their respective levels loaded are via hacking:
    • Open Your Heart Menu Version
    • Azure Blue World (Emerald Coast Act 1)
    • Windy and Ripply (Emerald Coast Act 2)
    • And...Fish Hits!
    • Limestone Cave (Icecap Act 2)
    • Tricky Maze (Lost World Act 1)
    • Danger! Chased By Rock (Lost World Act 2)
  • The Chao Garden background music is mixed and arranged quite differently from the final:
    • The melody is much quieter.
    • The backing brass and accordion are also much quieter.
    • The percussion is made up of standard instruments (what sound like maracas, drums etc) as opposed to the electronic beat used in the final, and is much more prominent.
    • There are additional flourishes to the backing brass near the end of the song (at about 1:20 in the track).
  • "Azure Blue World ...for Emerald Coast" (4.ADX) has several differences:
    • The drums in the introduction are lacking reverb and are missing some backing drums (it has less volume than in the final).
    • The cymbal hi-hats in the introduction are much quieter than in the final.
    • The lead guitars leading into the track's chorus sound unmixed.
    • The backing instruments are a mixed a bit louder throughout the track.
    • The synths are louder in the chorus.
  • "Event: The Past" (8.ADX) is missing the clarinet after the intro.
  • "Event: Fanfare for Dr.EGGMAN" (9.ADX) has its instruments panned differently.
  • "And...Fish Hits!" (12.ADX) is entirely missing the guitar solo in the second portion of the song, but has all the backing instruments.
  • "Run Through The Speed Highway" (13.ADX) has multiple differences:
    • The track as a whole seems slightly faster than the final version.
    • The "Right!" voice clip is slightly quieter.
    • The track's volume seems to get louder 54 seconds in.
  • "Goin Down?! ...for Speed Highway" (14.ADX) is longer than in the final - the background voice and laugh loops twice. In the final, those clips are only played once.
  • "Danger! Chased By Rock ...for Lost World" (19.ADX) has quieter mixing on the percussion.
  • The guitar solo in "Mt. Red, A Symbol of Thrill" (22.ADX) is an earlier, more messy take in this prototype.
  • Tails' theme (26.ADX) has heavy stereo separation that makes the lead vocals sound dull compared to the final.

Enemies and Objects

  • Reflections on the spike balls are completely broken.
  • Rockets use a different model for their launchpads - they're larger with more detail, and small doors that flip up to open when the rocket comes out. The design here also forces the player to jump onto the platform to access a rocket - in the final, part of the platform is lowered so the player can just walk up to it.
  • Jump ramps lack their sounds and are largely broken, generally flinging the player into incorrect locations or not high enough to continue.
  • Only large springs are used in this build, lacking the small springs that occasionally crop up in the final.
  • Checkpoints are not activated when the player respawns at them, so the player has to run through them again to activate them after death.
  • Item boxes have a green tint at the bottom that is not present in the final.
  • All the life icons except Sonic are facing right. In the final, all of them face to the left.
  •  ? ring boxes show the ? icon to the player when broken instead of showing the corresponding icon for the number of rings given.
  • Only icons for 5 and 10 boxes exist in the game - the icons for 1 and 50 ring boxes are missing.
  • Likewise, the Bomb, Invincibility, and Shield item box icons, as well as the Timer icon unused in the final, are also missing, and none of these items are placed anywhere in the autodemo's levels.
  • Kikis have even more of a tendency to blow themselves up.
  • Bombs thrown by Kikis cannot be thrown by picked up by the player.
  • Rhinotanks are using incorrect textures, looking orange instead of blue and having broken jet trails behind them. This is because their actual textures are missing from the build entirely, but the game still references them.
  • The Sweeps (water strider badniks) don't float on the surface of the water like they should - they're always underwater but animate and act like they do in the final.
  • Leon, the chameleon badnik, is present within the game's files but isn't actually used by any of the build's levels. If loaded in via hacking, the tongue attack does not hurt the player and the enemy itself cannot be harmed by the player.
  • Characters have no voice clips when immobilized by an Egg Robo.
  • End level capsules don't spawn Chao animals when broken open.



  • Characters don't have any idle animations aside from those for standing still. They also don't talk after standing still for long periods of time.
  • While all characters have the pushing action implemented, Sonic is the only character who can do so for an extended period of time; everyone else will briefly push and then stop. Sonic is also the only character who actually has a moving sound implemented when pushing something as well.
  • Picking up objects is largely rough (if it doesn't outright crash the game, like listed below). Primarily, the game has problems choosing which object to pick up if there are multiple items nearby.
  • Sonic and Big are the only characters who can put down a held item without throwing it instead.
  • Held items cannot be shaken.


  • His standing pose is less close to the ground than it is in the final (his knees are less bent). This is especially obvious in the cutscene where he is squaring off against E-102 Gamma. This old version of the pose actually makes it into the final in some of its cutscenes.
  • Sonic's idle standing animation is faster than in the final.
  • Sonic can actually lean left or right when standing on sloped surfaces, as well as forward and backward. In the final, he only leans forward or backward on slopes.
  • Sonic has a far different version of the Light Speed Attack in this build. Before each attack, he will crouch (an animation never used outside of this version of the Light Speed Attack) and a blue sphere will rotate under the next target. When the action button is pressed, Sonic will hit that target, and then crouch again (even in midair), and process continues; when the B button is pressed, it becomes a normal homing attack. The system is really finicky - oftentimes the game will try to target thin air, and if there are no more targets in the area, Sonic will fly a very long distance. In the final, the Light Speed Attack autotargets and immediately hits a chain of nearby enemies when the player releases the action button after charging it.
  • The blue glow around Sonic when he uses one of the Light Speed skills has less green in it and is more translucent than in the final. It also has some intense flickering (though this could be due to quirks in emulation).
  • The targeting for the Homing Attack regarding springs is inconsistent in this build - sometimes it fails to lock onto them.
  • Some of Sonic's voice clips are of different - and more Engrishy - takes than in the final. For instance, his voice clip for clearing a level.
  • Sonic's death scream when falling into a pit kicks in so late that it plays while he's respawning at a checkpoint.
  • The numbered jump pads exclusive to Sonic's levels have a few differences:
    • An additional pad type exists that is not present in the final - a pad that isn't numbered but has the star texture that the springs have. It is used to denote the final pad in a sequence, where Sonic lands after successfully completing the entire sequence. In the final, none of these are present, so the area where Sonic lands after ending the sequence is just normal ground.
    • The pads themselves are less flat and more blocky. While in the final, the orange cover is recessed behind the edges of the pad, the pads in this build have the orange portions extending all the way to the edge of the model.
    • The numbers inside the pads are mapped differently than in the final - they are much larger and sometimes off-center, like in the case of the "1" numbered pad as seen in gameplay.
    • There is no "shockwave" animation effect when Sonic lands on a pad.


  • Tails' idle standing animation loops faster than in the final, especially for his tails.
  • Tails' "tired" animation when flying is broken - he just stands while he falls. He also has a different voice take than the final.
  • Tails is missing his animation for jumping while carrying an object.
  • Tapping the action button repeatedly will have Tails continuously spin-attack, complete with the dance animations like when he has the Rhythm Badge upgrade. In the final, his spinning is much more spaced out until you get this upgrade, which allows you to spin repeatedly by holding the action button down.
  • Tails has no sound effects for spin-attacking.
  • Tails' textures for his mouth, nose, and eyes keep disappearing and reappearing during cutscenes.
  • Sonic's voice clips for racing Tails don't seem to be implemented yet - for instance, in the Icecap demo for Tails, no clips are played.
  • The texture file for the Eggman that Tails races in Speed Highway has a trailing _1 in its filename (MRACE_EGGMOBILE_1.PRS) that is not in the final version. The textures in this build have minor differences from the final ones used.


  • Knuckles has a large amount of unused combat animations in this build, including some seen in pre-release footage and screenshots. They seem to be axed by this point, as Knuckles doesn't use any of these extra animations while attacking in the demo or if the player is playing as him via hacking.
  • Knuckles can dig without the Shovel Claw upgrade.
  • The sound effect for gliding takes a bit longer to kick in - roughly a full second - after the gliding animation starts, and doesn't fade out.
  • Stars appear if Knuckles glides into a boundary. In the final, no particles like this are generated.
  • Trying to pick something up as Knuckles crashes the game.
  • Occasionally, punching Rhinotanks as Knuckles will also crash the game.


  • Amy's hammer isn't visible when she runs at top speed.
  • Amy's hammer animations lack the trailing hearts.
  • Amy's hammer attacks have no sound effects.
  • Amy's falling animation has her skirt flip up all the way to her chest. In the final, it doesn't go up nearly as much and she leans forward.
  • Amy crashes the game when certain actions are attempted by the player. These actions are:
    • Attempting the hammer backflip (attack button while running) outside of one of the game's demos.
    • Attempting to use the hammer in midair.
    • Attempting to shake one of the trees in a Chao garden.
    • Attempting to pick something up. She also lacks an animation for jumping while holding an object, likely because of this.
  • The question and exclamation marks above Zero's head look different and far blockier from the final.
  • Zero's targeting reticule is a solid triangular prism - in the final, it's a triangular wireframe.
  • Amy makes a sound when targeted by Zero that is not present in the final.
  • Zero is using entirely different sound effects - for instance, using constant "swishing" noises while using its targeting laser (in the final, it's a high pitched squeal similar to Gamma's).
  • Zero doesn't seem to have sound effects for it hitting its hands together while chasing Amy.


  • Big's idle standing animation is rougher than in the final - he bobs more prominently, his ears don't move, and the animation loop is much faster.
  • Big has a voice clip that plays alongside his jump noise during every jump. In the final, he just has the jump noise when he jumps.
  • If the player has control of Big (as opposed to being in a demo), pressing the action button at any time will cause a crash.
  • The UI that shows up when Big has his line out is rougher:
    • The text (Line [x]m) isn't vertically centered and the black area around it lacks rounded corners on the right side.
    • The line meter is placed in the middle relative to the text (in the final is to the right), and the UI itself is vertically centered on the screen instead of being in the bottom right corner.
    • The line meter doesn't change color according to how close the line is to breaking (it just stays the same shade of light blue the entire time), and the meter itself is visibly shorter than in the final.
  • Big's HUD is also different:
    • The weight value does not use darkened numbers. In this build, his weight is also hard-coded to be set to 12345g.
    • While there is a ring count icon, no numbers (not even zeroes) are populated.
    • The HUD has the LEVEL item noted above, and it still serves no purpose here.
    • There isn't the standard lives counter in the bottom left - instead there are lure icons in the top right to denote lives.
  • As seen above, Big's mission graphic for catching Froggy says "Go fishing for your friend frog" - in the final it says "Fish for and catch Froggy!". "Your friend frog" is a direct translation of Froggy's Japanese name, kaeru-kun (literally "frog" with the "-kun" honorific added).
  • When Big hooks something, the "HIT!" text does not appear and the "And...Fish Hits!" track does not play, though the track is present in the build's files (see above). No voice clip plays when Big hooks Froggy.
  • Froggy's tail is much more visibly separate from the rest of his body than in the final.
  • Froggy has no struggling animations when hooked by Big - he just lazily swims along while hooked.
  • Big's catch animation loop (when he holds Froggy/the fish he caught over his head) is much faster than in the final and seems to have fewer frames of animation. No voice clip plays when he catches Froggy.
  • The Get Chaos Emerald jingle from Sonic 2 plays when he starts his victory dance (in the final it plays a ring sound when the weight gets added to the total), and the camera does not zoom in to him like it does in the final.
  • The build is set to load an additional binary file (SAKANA.BIN) if a certain test stage is loaded. This binary file contains object code for fish, and was likely used in a test map to test his fishing mechanics.

E-102 Gamma

  • Gamma's theme in cutscenes starts at what is the midpoint of the song in the final version of the game.
  • Gamma is the only character in this build that actually has a visible upgrade item in gameplay - the Jet Booster. In cutscenes it will also sporadically appear (see below).
  • Gamma will quickly go into his gun-holding idle pose if he comes to a stop. This can also briefly be seen in one of his cutscenes (see below).
  • When Gamma "runs" (crouching down and using the wheels on the back of his feet), there is a very loud high-pitched noise.
  • Gamma's jumping noise is different from the final.
  • Gamma can jump when in propeller mode (when he gets near a body of water). In the final, he just hovers - pressing the jump button does nothing.
  • Animals used in raising Chao can be targeted and shot at. The wireframe targeting icons and blasts fired at them persist forever, even after being picked up and held by Gamma, and they can't be targeted again in this state. Trying to give an animal that has a blast fired at it to a Chao will harm the Chao.
  • Gamma's "shaking tree" animation completely clips through the tree he is trying to shake.
  • Gamma has no voice clips when breaking item boxes.
  • Gamma's gun has textures in a separate file in this build (E102ITEM.PRS). In the final, they are included in his character texture file instead.


  • Despite not appearing in any of the autodemo's cutscenes, her textures are present in the build.


  • All boss levels except for Chaos 2 will crash the game if the player attempts to access them through the level select. This could be because all boss levels except for Chaos 2 also lack their actual bosses.

Chaos 0

  • The only difference is there's no windows at the door.

Chaos 2

  • The arena that this boss takes place in (the Station Square hotel area) is completely untextured and empty.
  • This build has a camera file for Knuckles' boss fight (CAM1600K.BIN) - the game actually has the camera hard-coded to always focus on Chaos, thus making this redundant. The file itself is blank (indicating that it was already scrapped at this point), and does not exist in the final.
  • This build also has a camera file for Sonic (CAM1600S.BIN, with the S suffix for Sonic), which is particularly interesting given that in the final, Chaos 2 is a Knuckles-exclusive boss fight.
  • Chaos 2 itself does spawn in the level, unlike all of the build's other bosses. Chaos will not move nor try to attack the player, though the player will still be harmed by collision damage. Chaos itself is also untextured, showing up as bright white.

Chaos 6

  • Has two versions of the boss' map - one of them is compressed as PRS like it should be, but the other (LAND1800.BIN) is left uncompressed and left in the directory. The uncompressed one three days older than the compressed version, and has only level geometry - no programming or object models.
  • Knuckles' version of this fight is completely missing from this build - no level slot.

Perfect Chaos (Chaos 7)

  • The build contains a texture file for this boss fight (LM_CHAOS7.PRS) that is far smaller than the one used in the final (LM_CHAOS7_0.PRS) and lacks the final's trailing 0 in the file name. This file is dated the same day as the stage texture file, B_CHAOS7.PRS. Some of the buildings don't load the correct textures, which appears to indicate that this file is for a different version of the stage.
  • B_CHAOS7.PRS does not map properly to the level's geometry in this build.
  • The level geometry is entirely different from the final - there is only one linear stretch of buildings. In the final, it is a loop layout, so that Chaos and Super Sonic can repeatedly fight without having to keep turning around.
  • The buildings that appear on the sides of the level are much taller than in the final.

Egg Hornet

  • This build has a camera file for Sonic's boss fight (CAMEGM1S.BIN) - the game has the camera hard-coded to always focus on the Egg Hornet, thus making this redundant. The file does not exist in the final, likely for this reason.
  • The arena uses a rough, early model of the Mystic Ruins, much like the maps for Casinopolis below. It lacks any structures or details, just containing the basic world geometry.

Egg Viper

  • The map that this boss starts in is Act 4 of Final Egg in this build. In the final, this map is part of the boss fight map (albeit far below the actual boss fight at Y:-50000). This version also lacks the area where Sonic enters the fight in the final's cutscene. The textures for this stage will not load in-game.
  • There are two copies of the object file used in this build: SET1004S.BIN and SET1005S.BIN. The file is outdated and the objects that appar in this level are the same as the final, which means that clusters of objects will spawn in, like in Knuckles' Speed Highway below.

Egg Walker

  • Is completely missing from this build - no data whatsoever, and no level slot.

E-101 Beta

  • The first battle with E-101 Beta in Gamma's story is completely missing - no data, no level slot. The second one (vs Mark II) has a level slot however.

E-103 Delta

  • While present in this build, it goes unused due to the lack of a set file for Gamma's Windy Valley.
  • The title card for this boss just reads "E-103" (with no Delta at the end) in this prototype. This is due to the boss font lacking the Delta symbol at this point in development.
  • This boss is actually relatively intact - like in the final, E-103 takes five hits to beat, and the game will actually use the clear stage sequence, ending with a Coming Soon! screen and going back to the title.
  • E-103 cannot be harmed while it is gliding in mid-air with the Jet Booster, because once it starts gliding, it never lands.

E-104 Epsilon

  • E-104's boss fight is present in the game if the player manages to load up Gamma's Red Mountain and proceed through it.
  • E-104 does not experience any knockback or visual effects when hit.
  • E-104 also does not release an animal when defeated.
  • The boss music (Heartless Colleague) does not play during this fight.


  • This build has a camera file that might be for Sonic (CAMROBOS.BIN), given the "S" suffix that denotes it. However, the file name itself is very different from what its corresponding stage file would be (B_ROBO). Like with Chaos 2 and Egg Hornet, the game has the camera hard-coded to always focus on Zero, so this file is redundant and not included in the final. It is also blank, indicating that it had already been scrapped prior to this build.
  • This build also has a blank set file for Sonic (SETROBOS.BIN). The set file used in the final has the file name SETZEROA.BIN, though a SETZEROS.BIN does exist in the final Japanese build (but obviously unused, as Sonic does not fight Zero).

Adventure Fields

  • Only the Egg Carrier and the Casino area of Station Square can load in the proper objects and textures in-game, because they are the only areas that are used in the Autodemo's cutscenes. The other areas are in the game but are missing objects and textures, and will crash or will send the player back to the title screen if accessed in-game.
  • The reason why is 8C768B38 (2C768B38 for Demul) is set to 5, to prevent it, set it to 4 in Cheat Engine.

Station Square

  • The level has SET files for each area, but four out of the six are blank.
  • Nearly all of its textures are missing, though the levels make reference to them.
  • Contained in the build is the file ADV00OBJ.PRS. This is object/code data for this adventure field - in the final, this code is within ADV00.PRS, but in this build it is its own separate file.
  • This adventure field in particular has several odd camera files:
    • The filenames have the format "CAMSETSS##S.BIN". The final files used, which also present alongside these in the build, use the format CAMSS##S.BIN instead. Oddly, the files that use the final filenames are actually much older than these unused ones, and contain nothing but blank data.
    • CAMSETSS00S.BIN is a camera file for Station Square City Hall as Sonic, and actually has some camera data in it. It is dated September 21, 1998.
    • CAMSETSS01S.BIN is a camera file for Station Square Casino as Sonic.
    • CAMSETSS02S.BIN is a camera file for Station Square Sewer as Sonic.
    • CAMSETSS03S.BIN is a camera file for Station Square Train Station as Sonic.
    • CAMSETSS04S.BIN is a camera file for Station Square Hotel as Sonic.
    • CAMSETSS05S.BIN is a camera file for Station Square Twinkle Park as Sonic.
  • The water is present, but is invisible due to the map being incomplete.
  • The lighting files are present and identical to those used in the final, but are unused in this build.
Main Area (Station)
  • The hotel has a giant "HOTEL" sign over its entrance.
  • The entrance to Twinkle Park is entirely different, and more castle-like. In the final, it is more futuristic, possibly indicating that the kart track the level opens with came after this version of the Adventure Field has made, and the exterior was updated to have a more futuristic feel to match that.
  • The water/sewer area that Big can get a lure and where Tails can go to get the Air Anklet has a much lower ceiling.
  • The slope between the street and the beach is less drastic.
  • The dock that leads to the boat that would take you to the Egg Carrier is missing entirely. This implies that originally, the player might not have been able to go back to the Egg Carrier after clearing the game.
  • The CYBER-NET INC building that Sonic and Tails both enter Speed Highway from is much taller in this build.
Twinkle Park Entrance
  • Its file is just a copy of SETSS00, the City Hall area (see below).
Hotel Area (Inside)
  • The player does not have a spawn point for this area.
  • The room has a chandelier hanging on the ceiling that is not present in the final (likely removed to make room for the Crystal Ring puzzle).
  • There's a ladder leading up to the area that has the Crystal Ring in the final; it can be seen in some really old pre-release screenshots. The area also has wooden railings. In the final, there is no ladder or the railing blocking it off - Sonic has to use the Light Speed Dash to get there.
Hotel Area (Outside)
  • The tables and chairs are arranged a bit haphazardly around the pool area, as seen in some pre-release screenshots. In the final, they're all lined up against the building.
  • The area near the shallow end of the pool (where the steps are) has only rows of long chairs alongside the building - in the final there are long chairs and tables.
Casino Area
  • The train station has no entrance.
  • The stairs leading to the train station entrance cannot be walked up - the player has to repeatedly jump to ascend them.
  • You can walk along the train tracks. In the final, the tracks are enclosed in glass can thus cannot be reached by the player.
  • The front of the hotel has no collision.
  • The billboard across from the casino entrance does not advertise Chao In Space, instead advertising The Man 3, though only the top-left of the texture is shown. The full texture can actually be seen in the final during the Egg Walker boss fight, indicating that the boss arena is based off of this version of the casino area.
  • There is a poster above an awning in the alley that is not in the final.
City Hall
  • Largely identical to the final, with only a few changes.
  • One door on a building next to the sewer appears to be reflective glass instead of using a texture like in the final.
  • The rock used to swap for the Gold Chao Egg is missing.
  • The emblem inside the burger shop is missing, as is the Burger Man statue that can be picked up and carried.

Mystic Ruins

  • All of its landtables crash level viewers. The game will also crash if the player attempts to access it from the level select.
  • Extracting the level geometry itself shows some minor changes:
    • The monkey cave near the entrance to the Chao Garden has a different shape.
    • The ledge where Sonic can find the Ancient Light upgrade is missing.
    • The bridge to the Master Emerald shrine is of a slightly different shape.

Other than these changes, the level geometry is the same is the final.

  • Contained in this build is the file ADV02OBJ.PRS. This is object/code data for this adventure field - in the final, this code is within ADV02.PRS, but in this build it is its own separate file.
The Past
  • Is completely missing from this build - no data whatsoever and its level slot is actually occupied by Twinkle Circuit.

Egg Carrier

  • There are a few texture files for this adventure field that likely got merged into other ones in the final to cut down on load times:
    • OBJ_EC_AB.PRS, OBJ_EC_C.PRS, OBJ_EC10.PRS are all files for the exterior of the Egg Carrier, likely merged into OBJ_EC00.PRS in the final.
    • OBJ_EC31.RPS and OBJ_EC33.PRS are both files for the interior of the Egg Carrier, likely merged into OBJ_EC30.PRS in the final.
  • A set file for the external area of the Egg Carrier exclusive to Gamma exists in this build (SETEC31E.BIN). In the final, this file does not exist, because all characters use the same set file as Sonic. It is the only set file in the entire build to have a September modification date - all the others were last updated in August.
  • Attempting to load any of the Egg Carrier exterior areas through normal play will load in Sonic's cutscene with Gamma instead.
Outside (Untransformed)
  • Does not load up the correct textures and objects, as no cutscene in the autodemo is set here.
  • There is no boat docking to the other Adventure Fields.
  • There is no spring leading up to where Chaos 6 is fought.
  • There are item boxes near the Bridge.
  • There are rings placed here, in circles and lines. These include circles on the lower decks, a line close to where the monorail is supposed to come out, and a circle of rings on the arena. In the final there are never rings placed in the Adventure Fields aside from the ones Knuckles can dig up.
  • There are no buttons to call the monorail.
  • The springs from the Tornado's crash site point straight up, instead of at an angle.
  • The boxes placed at the base of the cannons near the arena area are breakable and have item boxes in them, including speed shoes, which never make an appearance in the Adventure Fields in the final. Sonic can only break them open with the Light Speed Attack.
  • The arena area has a center that sticks up - in the final, it is flat. The low-detail version of this when viewed from the back of the ship while it is transformed actually shows up in the final, but it is hard to see.
  • The angles of the cannons are incorrect - the player will always hit the field's upper boundary when shot out of them, causing a visible collision between the player character and an invisible barrier, as well as a rapid and visible decrease in height.
  • The curved pillars that connect to the central area have no collision - the player clips right through them when shot out of cannons.
  • The tall platform near the entrance to the bridge is missing the spinning platform on top of it.
  • The tall platform near the entrance to the bridge has a cannon that shoots the player to the roof of what would be the pool area.
  • There are item boxes, including an extra life, hidden on a ledge behind the outside of the pool area.
Front Deck (Transformed)
  • The build's texture file filename for this version of the adventure filed is lacking the underscore its final counterpart has.
  • The exits are broken, and only a few can be fixed by giving them the values of their final counterparts.
  • There are item capsules outside of the entrance to Sky Deck.
  • Most of if not all of the changes listed above for the untransformed version carry over here, including the lack of monorail buttons, the upper boundary with the cannons, the rings placed, and the springs to the area where Chaos 6 is fought.
Rear Deck (Transformed)
  • Sonic has a cutscene set here in the autodemo, so the textures and objects load in correctly.
  • Behind the building containing the swimming pool is two ? Ring Boxes and a 1-UP. In the final, it is instead two 10 ring boxes.
  • The tower has the cannon that shoots the player to the roof of the pool area, like in the untransformed exterior field. This is not present in the final.
  • The spinning platform at the top of the tower that is missing in the untransformed version of the exterior is also missing here, as is the 10 ring box that is supposed to be placed slightly below it.
Captain's Room
  • The scanners up in front are not visible.
Captain's Room (Lower)
  • The positions of the button panel and one of the doors is switched, but improperly - the arrow button panel is just floating in mid-air in front of a hole in the level geometry, while the frame of the door is embedded in the wall with no opening.
  • The layout is flipped - the living quarters is on the right of the layout instead of the left.
  • Pressing one of the arrow buttons lights the doors up for a short time.
  • The bright pink disco room has a door that leads immediately to a wall embedded inside of it.
  • There is no switch to activate the trail of rings leading to the upper captain's room, so you have to get up there via dodgy spin dash physics.
Pool Area
  • There is an inexplicable hole in the level geometry on the opposite end of the pool from the entrance. Naturally, falling into it kills you.
  • There are no item boxes near the top of the area.
  • There is no spring at the bottom of the pool.
  • The textures and objects load properly here, due to Gamma having a cutscene taking place here in the autodemo loop.
  • The lighting here is slightly less green and is darker in general than in the final. The doors themselves are lit rather brightly.
  • The build's texture file filename for this version of the adventure field is lacking the underscore its final counterpart has.
  • The top deck of the back of the bridge, where the rooms leading to the cells and Hot Shelter are, have two rows of rings and a few ring capsules.
  • The entrance to the Chao Garden is missing its puzzle.
  • There are no hint monitors.
  • The robots moving along the left and right sides of the upper deck are missing.
  • The arches going over the room lack collision.
  • The pod exit out of the bridge is also lacking collision.
  • The bottom deck has five maid robots scrubbing the floor. In the final, there is only three.
  • Like in the outside areas, the monorail and the buttons to call it is missing here.
  • The room that normally has the Chao Garden teleporter is empty in this version, only containing a door that lacks an exit object.
  • The small rooms attached to the bridge (that in the final have Gamma's upgrades) only contain doors and their corresponding exit objects.
  • The Hedgehog Hammer room is completely empty save for the doors on both sides leading to the cells and the bridge, respectively. These doors have no exit objects.
  • The build's texture file filename for this version of the adventure filed is lacking the underscore its final counterpart has.
  • The lighting is different, and is lacking the fog seen in the final.
  • It loads in textures and objects properly due to a cutscene with Amy and Gamma being present in the autodemo loop.
  • The cells make no sounds when opened.
  • The middle cell has a ? Ring box and a 1-UP. In the final, a black Chao egg is here instead.
  • The rightmost cell is missing Big's lure upgrade.
  • The fans below the floor spin more slowly.


Test Level (STG00)

  • This is a series of test levels used to test the game's physics and pathing systems, and were replaced with the Hedgehog Hammer minigame in the final. The file contains three sets of level geometry:
    • The first test level contains structures such as loops and slopes in various configurations. It also has some thin paths and floating platforms. It has three models. This test level will crash the game if the player attempts to load it.
    • The second test level contains structures such as slides and tubes (of which there are many), a pinball-rail-like track, a deep conical region, and an area consisting of wavy slopes. This test level will also crash the game if the player attempts to load it.
    • The third test level tends to crash level viewers and consists of twelve models. It is entirely missing references to textures. It tests paths for scripted sections.
  • Also present in the build are set files for all three test levels. All the set files have the same object layout.
  • At the end of STG00.bin are some strings, alongside what their English translation would be:
    • ジャンプ中にもう一度 ジャンプボタンを押して。 (Press the jump button once more while jumping.)
    • ホーミングアタックよ。 (It's the Homing Attack.)
    • テストメッセージです。 (This is a test message.)
    • ソニックと E-102でだけ出る予定です。 (The plan is to go out with only Sonic and E-102.)
    • ソニックです 音声データは適当です。 (It's Sonic. The voice data is unfinished.)
    • マイルズです ナックルズですです 飽きたので残りは一まとめです。 ("It's Miles It's Knuckles Since I got tired all that's left is a single collection." Of note is that for some reason the trailing "desu" at the end of the "It's Knuckles" portion is here twice.)
    • メッセージ1 メッセージ2 (Message 1 Message 2)


  • Completely unplayable - it cannot be loaded in-game even with hacking, because the game crashes when its land table is loaded.
  • All of the level geometry for the acts of this stage are rough, early models.
  • The SET files are blank, except for the Sonic pinball table level, which specifies all of its level specific objects (flippers, starting point etc).
  • All of its maps completely lack references to textures.
  • Tails has no initial coordinates for any parts of this level.
Main Hall
  • The flat neon sign of a cowgirl holding a drink, seen in the JP final version of the game, is instead a giant bunny girl statue holding a drink, lying down next to a minibar in this version.
Dilapidated Way
  • There's a small, winding tube structure leading to what is the beginning of this level in the final. This path does actually exist in the final (albeit unused and impossible to access in normal gameplay), which indicates that it might have been scrapped at the last minute.
Sonic Pinball
  • The level geometry is largely the same as the final with a few differences:
    • There's a complete tower in the right side of the table. In the final, only the bottom of its geometry remains.
    • There is geometry for more tower-like structures in the left side of the table. In the final, these are not present.
    • The dividers where the ball enters the table proper are narrower and less round than in the final.
    • The prototype table is missing two squareish structures near the middle of the table that are in the final.
NiGHTS Pinball
  • This is actually the prototype pinball table seen in some very old screenshots of the level. It is a spiraling, sloping area that Sonic would have to make his way up using flippers placed on certain parts of the level, but there is no way out in the land table.
  • It only has a few of its own unique objects in its object list and not much else.
  • It tends to crash level viewers.

Emerald Coast

  • The level as a whole has dimmer lighting than the final. This is especially obvious at the beginning of Sonic's Act 1 when you look at the sand texture.
Sonic's Emerald Coast (Act 1)
  • Is unable to be finished via normal play due to how incomplete the level is.
  • Sonic spawns in mid-air, and when he lands, the camera angle is lower to the ground than it is in the final.
  • The palm tree objects in the beginning have models that are more curved and are placed in slightly different locations.
  • The beginning completely lacks enemies and breakable table and chair objects.
  • There are no item boxes hidden at the beginning of the level.
  • There are two Rhinotanks at the beginning of the elevated bridge area instead of the one in the final.
  • The springs don't send you the correct distance, which tends to make you miss the elevated path in the second part of the level. There are also only four of them - in the final, there are five.
  • There are no spike balls in the sandy area after the first set of springs.
  • The path after the first set of springs lacks the bouncy ropes on the sides.
  • There is only one spring to get back up to the elevated bridge area - in the final, there are two.
  • There is no spring in the air before the level's first loop.
  • There is only one dash pad leading into the loop - in the final, there are two.
  • The camera has a different angle when Sonic goes through the first loop - it is pointing to the loop's right side rather than the loop's left side.
  • The first loop in the level doesn't send Sonic up as high.
  • There are Rhinotank enemies after the first checkpoint - in the final there are only Kikis.
  • There is no item capsule hidden behind the island directly after the first checkpoint.
  • The launcher after the first checkpoint doesn't send Sonic high enough, dooming him to the bottomless pit in normal play.
  • The spike walls make no sounds and bury themselves deeper into the ground upon descent than they do in the final.
  • The path after the launcher allows Sonic to run up its walls and ceiling.
  • The curved slope that leads you to the level's second loop is broken - Sonic loses all momentum after getting to it, even with the booster pad right before it.
  • The path leading directly to the level's second loop has dodgy collision on its sides, so Sonic can occasionally clip through and fall to his death.
  • The camera is completely broken before the second checkpoint - it is below the platform if not clipping through it, which makes it really hard for the player to see where Sonic is.
  • The whale sequence is not implemented yet: no whale spawns, the camera is broken throughout the entire segment, and the walkway Sonic runs on during the sequence just goes in a straight line before abruptly stopping. As a result, the act is impossible to clear in normal play.
  • The camera doesn't transition back to behind Sonic (it's still in front of Sonic from the whale sequence) until after he passes through the first spike gate. In the final, the camera immediately changes back to being behind Sonic when he reaches the final part of the act.
  • There are no item boxes on the island's east side.
  • There are no item boxes on the floating island above the island's east side.
  • There is no wind object keeping Sonic from falling off the path at the lighthouse.
  • The lighthouse rails have Kikis on them where there are none in the final, while the Kiki above the entrance to act 2 is missing.
  • The transition to act 2 is not present yet.
Sonic's Emerald Coast (Act 2)
  • Sonic starts Act 2 facing away from the path.
  • There is no back wall at the entrance, just a hole in the geometry leading to a bottomless pit.
  • The first part of Act 2 is completely missing the waterfall object.
  • The wall Sonic can run on at the beginning of the stage has a different ring layout. There is also no Speed Shoes capsule.
  • The springs from the shortcut (which you get to by running on the wall) have broken distances and don't lead Sonic anywhere.
  • The area the springs are supposed to lead you to doesn't have the booster pads or the extra life it has in the final.
  • The water area on the lower path has no floating platforms, and there are three Sweeps rather than the two in the final. It is also missing the circle of rings directly after it.
  • The spike wall in the lower path has a 10-ring box after it where a Kiki would be in the final.
  • The large loop has fewer rings before it and no dash panel directly after it.
  • The launcher leading to the next part of the level doesn't work at all, making this act also impossible to complete in normal play.
  • The booster pads for the ramp in the second part of the level tend to send Sonic flying off of the ramp, which also means that the ramp's railings don't have collision.
  • The path that the ramp leads you to has no railings.
  • There is a Kiki standing in the air before the arch of rock you go through.
  • The set of rock step-like formations on the path in the final are instead a grass ramp-like formation here that is harder to traverse.
  • The camera just cuts to a new angle after Sonic goes through the small tunnel - in the final it follows him through and then swings around.
  • The act's second checkpoint is missing.
  • The platform where the second checkpoint is in the final is missing some of its railings.
  • The ramp after where the second checkpoint should be is missing all of its booster pads.
  • There is no hint orb where the numbered jump pads are.
  • The item boxes off to the left in the final are missing here.
  • There is no spring that allows you to skip the numbered jump pad sequence. However, there is still a spring in the skip sequence that will launch you to your death, should you happen to get there.
  • The numbered jump pads are arranged a little differently than they are in the final. There are also only four panels instead of five - the second panel is missing here.
  • The extra life in the alternate path for the numbered jump pad sequence is instead a ? ring capsule in this version.
  • The area Sonic ends up at after the numbered jump pad sequence has no railings or spiked gate obstacles.
  • The path before and during the level's last loop has no booster pads, and the loop itself has no pathing object.
  • The final stretch of the level is missing all rings, enemies, and decorative objects. There is also no end of level capsule here or crashed Tails, which again makes this level impossible to complete in normal play.
Big's Emerald Coast
  • This is one of the levels demonstrated in the autodemo loop.
  • Big starts out in the island cave that is secret in the final version. In the final, he starts out at the end of Sonic's first act.
  • There is a light effect object shining in from the top of the cave that is unused in the final.
  • There are no fish that can be caught here, though there are small decorative fish. Only Froggy can be caught.
  • Froggy is weak and doesn't struggle much, and Big's line is impossible to break even if the visible reel gauge hits its maximum.
  • Big cannot leave the island cave because the exit is blocked by a rock.
  • The level outside the cave is Big's level geometry but Sonic's object layout. Sonic's object layout here is actually from a later version than what is used in this build - items noted above as missing, such as the ropes on the bridge, springs, and decorative objects, are present here!

Speed Highway

Sonic's Speed Highway (Act 1)
  • This level is one of the ones demonstrated in the autodemo loop. The lighting system seems to be functional in this stage, though in practice is a little different from the final. The contrast is toned down in this version (bright spots look less bright, dark areas less dark).
  • The opening camera angle is different from the final - it is far closer to the ground. The opening section also has a much lower ceiling, perhaps being why this camera angle is used.
  • The walls in the opening section also have a different texture.
  • The platform to the right of the opening section is a 1-Up in this version. In the final, it is a magnetic shield box instead.
  • Two of the large buildings at the beginning have three rings on them. In the final, these are 1-UPs instead.
  • The three item boxes in the middle of the buildings at the beginning of the stage are two 1-UPs and a wild card ring box. In the final, they are two 5 ring boxes and a 1-UP.
  • There are extra hint orbs throughout the level.
  • When Sonic pushes on the barriers, a metal-scraping sound effect plays. In the final, no sound is played.
  • Sonic isn't propelled off the ground after the first set of freeways, and instead is running directly on the glass afterwards. In the final, he is propelled quite high before landing on the glass.
  • The object layout before the first checkpoint is different: there are more rings before the row of rings leading up to the spring and an extra hint orb.
  • The moving platform section before the first checkpoint is missing rings entirely.
  • The speed shoes box on the platforms in the lower area is also missing.
  • To the right in the lower path, there is an empty building that has a Cop Speeder, rings, and a 1-Up in the final.
  • The slope on the lower path before the bell tower has six rings instead of eight.
  • The bell seen in this act and in At Dawn (at the end of the level) is using a completely different model and textures, and is placed lower than in the final. It also has no animation when hit.
  • Below the bell area, there are two 10 ring boxes. In the final, there is instead one 10 ring box and one shield box.
  • The dash panels leading out of the bell area are missing the rings in front of them.
  • The end of the tunnel in the lower path has two rings that aren't present in the final.
  • Sonic "sticks" more to the walls of tunnels, and moves more slowly going up stairs.
  • The sound when Sonic takes the flingers going up is very loud, with a lot of clipping. Don't watch video of this act with headphones on!
  • The double line of rings before the moving platforms section has six total rings here. In the final, it is four instead.
  • The upper path of the moving platforms area lacks the speed shoes box found here in the final.
  • The camera angle when getting to the extra life under the first set of moving platforms is slightly different.
  • Prior to the springs that sends you to the helicopter area, there are arrow signs that are not present in the final.
  • The hint orb near the helicopter does not having rings surrounding it like it does in the final.
  • When Sonic hits the spring taking him to the helicopter, he is facing the camera with his back towards the helicopter. In the final, he is facing towards the helicopter with his back towards the camera.
  • The camera angles when Sonic rides the helicopter are different.
  • If Sonic rides a helicopter when a hint is playing, the caption will flicker.
  • The speed shoes box after the helicopter sequence is missing.
  • The secret platform you have to homing attack to has two extra lives, instead of one like in the final.
  • The bottom of the large circular building in the lower path to the end of the stage is lacking the circle of rings.
  • The slope leading out of the building has a line of four rings instead of a square.
  • The line of six rings at the dash pads after the moving platform is instead a line of four in the final.
  • The large building on the lower path has a different object layout. Here, it has two squares of four rings, three Cop Speeders, and a 10 ring box with a semicircle of rings around it. In the final, the 10 ring box is instead a shield box surrounded by a square of rings, and the layout has an additional two more squares of rings, three 5 ring boxes, and two Uniduses.
  • The second moving platform in this section has no rings.
  • The end of the middle path where it meets with the lower path is missing its line of four rings.
  • The area preceding the place with the rocket at the end of the stage has two lines of three rings here. In the final, it is three lines of four rings.
  • The area where the rocket is is lacking the Spinner and the bomb item box.
  • A line of two rings next to the rocket is instead a line of four rings in the final.
  • The Tikal hints for this act are as follows:
    • ジャンプ中にもう一度ジャンプボタン!? それで簡単に敵を倒せるはずよ。 ([Press the] Jump button once more while jumping!? Then you should be able to defeat enemies easily.)
    • 落ちないように気をつけてね! (Be careful so you don't fall!)
    • Speed Highway is Sonic's 6th level in the final game, so as such, these hints about how his gameplay works are not present in the final.
Sonic's Speed Highway (Act 2)
  • A hint plays (with no captions) when the skyscraper run starts if the level is played normally; it doesn't appear if the level is shown as part of the autodemo.
  • There are no item boxes between the pillars at the end of the run. In the final, there is a ring capsule and a magnetic shield capsule.
  • The level has a capsule at the end of it, indicating that it is the end of the stage.
  • The circle of rings at the end of the act are missing.
  • The lobby Sonic lands in is missing most of its decorative objects - there are no posters/illustrations on the walls and the red-and-yellow chairs are missing, though the plants have spaces between them to accommodate those objects.
  • There are more plants on the ledges on the upper walls than there are in the final, and there is an extra potted tree object next to where the red and yellow chair would be.
  • The hallway that leads to At Dawn is blocked off with tile objects, but the trigger to load act 3 is still present, provided you glitch through the barrier via hacking. If the player accesses Act 3 in this fashion, the textures will not load properly.
Sonic's Speed Highway (Act 3)
  • This level can only be loaded through hacking. Alongside Windy Valley, this is one of the stages in this build that has some of the most drastic changes from the final, and also appeared in early screencaps of the game.
  • In the early screenshots of the game, the draw distance was longer and the game's skybox lacked buildings in the background.
  • This act uses Act 1's lighting file; Act 3's own file is missing.
  • The beginning area has several changes. The two Cop Speeders are missing, there is a checkpoint, the hallway Sonic exits to enter the stage is longer, and the road itself is wider.
    • The checkpoint would be redundant in the final game, given that act transitions themselves act as checkpoints. It could be that this wasn't the case earlier in development, thus the checkpoint at the beginning of this act.
  • The building to the left as the player enters the level has a searchlight on it that is not in the final. The speed shoes box here is in a different spot and is lacking both the rings surrounding it and the containers near it.
  • This building also has a jump panel that leads the player all over the level. At 9 panels, it is longer than any set of jump panels used in the final game.
  • The sloped path going up a wall directly at the beginning of the level has a different, stripey texture that abruptly starts from the sidewalk. In the final, it continues to use the sidewalk texture for the entire path.
  • The signs hanging off the wall above the sloped path have different textures and are physically smaller.
  • There is a flat area to the right of the sloped path that has a speed shoes box. In the final, this area is entirely replaced with building geometry.
  • The area after the level curves to the left at the beginning has a recessed courtyard (the "hole in the ground" seen in pre-release screenshots) with a small clock tower. In the final, it is a straightforward road and has Spinner enemies.
  • The building to the left of the courtyard has awnings and a platform with a ring on it - neither of them are present in the final.
  • The small ledge at the corner near the courtyard has three rings that are not evenly spaced. In the final, they are four rings and their spacing was fixed.
  • The sidewalk has more decorations, including plants and newspaper stands.
  • The path leading to the main street, like the path at the beginning of the level, is wider than in the final. Because of this, the glass panels Sonic can run across near the end of the path number 12 rather than 9.
  • This path also has four Spinners instead of the lone one the final has.
  • The area around the glass panels has more plants.
  • The first set of roofs you can run on have fewer decorative objects on top of them.
  • In the first stretch of road, theere are a lot more springs as well as some of the jump panels mentioned in the path above.
  • The entrance to the small tunnel Sonic can enter lacks a shield box. The ledge itself is narrower and does not connect directly to the tunnel.
  • A set of two rings on the ledge to the right of the panels were changed to three in the final.
  • The cars often float off the ground or clip through it - their mappings are likely for an older version the stage or the final version of the stage.
  • The side of the building leading up to the first tunnel the road goes through has a booster pad floating on nothing.
  • The side of the building Sonic can run along is missing its line of rings.
  • The building the player can run on of near the start of the road section around has a steeper roof with two Spinners on it, as well as arrow signs. While on this building, the camera goes to an overhead shot. In the final, there are no enemies, and there are instead containers, rings, and a 5 ring box, with the arrow signs being replaced by posters. The camera angle also stays behind the player.
  • An area that the player can access by jumping over to the right of the building's roof is missing its line of three rings.
  • The area that the player can jump across to to get an extra life has a different structure: the extra life is in a smaller spot and the ledge is much larger, and there is a spring that the player can use to jump onto the building in front of them to quickly get to the end. In the final, this is instead a small passage with a wall between it and the extra life.
  • The sides of the buildings after the tunnel have a bright orange brick texture. In the final they use dark brown textures.
  • The clock at the loop in the road has a different base, and there are two Cop Speeders near it that are not present in the final.
  • The cars stop when they see the player at a much farther distance than in the final, and also cannot harm the player in this build.
  • The sidewalk is lined with rings, dash panels, and springs, along with these items on ledges attached to the side of buildings. In the final, there is only one of springs - the player needs to break the Spinner enemy in front of it and the springs will send the player into a small tunnel.
  • This entire level goes downhill. In the final, it goes uphill instead.
  • The two points where the cars go through tunnels over buildings is entirely different. In this build, they are small, squat buildings with a brick texture, and the player can walk on top of them. In the final, they are large buildings that the player has to go through to progress. There is also only one point where this is necessary in the final - in this build, there are two sections like this.
  • The path where Sonic can run along a wall has a different object layout.
  • The final tunnel is a ramp and has arrow signs and a speed shoes box on top of it.
  • The fountain at the end of the area is completely different from the final - it is a raised structure with a bridge leading from a ramp on the top of the last tunnel structure in the level, and has chairs under it at ground level. In the final, it's just a fountain at ground level surrounded by plants and chairs.
  • The buildings in the center of the road area are different from the final. They only have two containers and their heights are different, and the tunnel with steps is also missing.
  • The Cop Speeders near the end of the stage are in different locations.
  • The spring to enter the small tunnel in the building near the fountain does not launch the player high enough.
  • The fountain has four rings that are not present in the final.
  • City Hall has many rings around it. The final version has a greatly reduced number of them.
  • There are three springs to the left of city hall and one spring to the right of it. In the final, there is one spring on the left and two on the right.
  • There are also dash panels in front of city hall that lead to the spring to the right of the building. The area is also missing its 1-up box.
  • The fire hydrants the player can break make no sound in this build.
Knuckles' Speed Highway
  • Knuckles' version of the stage has the same object and layout differences as above, except that his stage has an object list that matches the final version of the game (save for a few items added onto the end), and thus doesn't correspond to the objects in this build - loading Knuckles' level via hacking has incorrect objects placed everywhere, such as fountains where the breakable glass panes should be.
  • One of the extra objects used in this stage is a trash can that goes unused in the final. In this build, it is properly textured as well.
  • There's a spring on a roof near the beginning of the level (where Sonic starts) that allows Knuckles to just skip through to the other end of the level.
  • The player can still hunt for Master Emerald shards, but occasionally the third one will not appear, making the level impossible to complete. This is likely due to the shard spawning in non-existent enemies and objects.
  • The Cop Speeders use incorrect sounds, though they work properly in all other respects.
Tails' Speed Highway
  • Tails cannot be controlled by the player at all. Instead, he moves along a set path in mid-air, clipping through scenery and objects, eventually to his death later in the level.
  • Eggman is not present, and the mission card is the standard "Break the capsule before Sonic does".
  • One of the buildings exclusive to Tails' version of the level has a piece of geometry missing.

Twinkle Park

  • This level seems to have all of its textures and geometry intact, and appears to be largely similar to the final version in this respect.
  • This level was compiled in September, which means it can't be loaded without intensive hacking due to expecting a different version of 1ST_READ.bin.
Sonic's Twinkle Park (Act 1)
  • A camera file, CAM0300.BIN, exists for this part of the stage, but lacks a character suffix to indicate who would be using it (the camera file actually used by the game is CAM0300S.BIN, with the "S" for "Sonic"). This file's date is July 30, 1998, while the one used in this build is dated September 18, 1998; this file and the used one have few differences.
  • The bumper car ring at the beginning of the stage has a massive item (it is not an object and lacks collision entirely) in the middle of it.
  • The objects in this level's set file do not match with the layout of the stage - nothing seems to appear.
Amy's Twinkle Park (Act 2)
  • The end of the room of mirrors is different - in the final it makes it look like Amy has to walk into a reflection, whereas here it ends in a straightforward manner.

Final Egg

  • Final Egg has three extra stages in the stage listing and three SET files for those stages. These files are exactly the same as the files for the test maps, which means that FINAL 4/5/6 are in fact clones of the three test maps included with this build. There are also identical camera files for these. One of these is CAM1004S.BIN, which is a camera file intended for Sonic (given the S suffix) - this could actually be the camera file for the first test stage included in this build. CAM1005S.BIN is also included in this build.
Sonic's Final Egg (Act 1)
  • This is the only act with music, likely due to Amy's version of this stage being part of the Autodemo loop.
  • The end of level capsule that is spawned outside of the level geometry at the beginning of the stage in the final is present here as well.
  • Sonic spawns in the path leading up to the level proper. In the final he starts in front of the pink laser obstacles.
  • The beginning of the level lacks half of the laser objects, the spike balls, and the Egg Keepers, being more bare as a result.
  • There is no platform above the pair of spinning spike balls, nor the springs that would allow you to reach it.
  • The spinning spike balls are rotating much faster than in the final.
  • The corridor with the claw machines lacks rings.
  • What would be the first checkpoint in the final is missing here.
  • Amy's path is open instead of being blocked off, and it is completely missing all objects, including the switch to call the elevator and the boxes Amy can hide behind.
  • The area leading up to the rotating tunnel section is missing Spinners and the corner of laser objects walling off some item capsules.
  • A doorway leading to part of the second portion of Amy's Final Egg (where she has to figure out which door allows her to proceed) is present here. This is strange because:
    • In the final, the first elevator Amy takes brings her to a room that has the same level geometry as Sonic's version of the room, but different enemy layouts and no entrance to the massive conveyor belt room in Sonic's version. However, this has to be a different room from Sonic's (as opposed to the same layout as his) because the layouts leading up to their respective versions of the rooms don't in any way line up - Amy has to go straight up in an elevator but Sonic has a complete horizontal path to get to this room from where the last Amy path was.
    • Therefore, the fact that Amy's part of Final Egg is present in Sonic's version seems to indicate that Sonic's version of the room was used as a base for Amy's room but they haven't managed to implement it/split it off yet (Amy's demo of this level ends before the elevator comes down).
    • Sonic's version of Amy's "door" room is just the geometry, like the other Amy path Sonic can access. It has no objects, items, or enemies.
    • In the final, this path is blocked off.
  • The wall above what would be final's second checkpoint (the first checkpoint in this version of the level) is missing the chrome Eggman decoration.
  • Both conveyor belts after the checkpoint have spike walls. In the final only the first one you traverse has a spike wall.
  • There is an extra spike roller at the end of the fourth conveyor belt (the first one that faces east relative to where the checkpoint is facing).
  • There is no lower path for this part of the level - if you fall, you die.
  • The area that can be seen through the path after the first rotating section is missing most of the decorative objects, such as pipes, that can be seen in the final, instead being a black abyss with some blinking lights.
  • The level sections with the rotating areas you have to traverse are greatly misaligned, which means that the player just falls out of the level geometry and dies trying to traverse them. This means that the level is impossible to finish via normal play.
  • There is no transition to Sonic's Act 2 - only level geometry that abruptly ends and opens up into the bottomless pit outside of the level.
Sonic's Final Egg (Act 2)
  • Even more unfinished than Act 1.
  • Act 2 uses completely different textures for nearly everything in the level - primarily floor and wall textures. It has a different, more beige color scheme as well.
  • The starting area is a flat hallway. In the final, it slopes downwards.
  • All decorative objects are missing - spotlights, blinking lights on the platforms, cameras, etc..
  • There are no enemies in this stage, which means this act's platforming has to be done solely by jumping without the homing attack.
  • There are no rings or items, but there are checkpoints.
  • The large room that makes up most of act 2 is using completely different wall textures, and looks in general beige as opposed to the black and blue of the final.
  • None of the platforms in this level move, which makes completing this act through normal play impossible.
  • The camera angle while Sonic navigates the platforms is much farther away from Sonic than in the final.
  • The openings to the piping Sonic runs through are square instead of octagonal.
  • The color scheme of the piping Sonic runs through to get to the lower part of the room is using different textures, primarily for the floor, which is the purplish metal grate of the last part of act 1 instead of the final's blue steel texture. The area itself is missing the blue glass that makes up part of the ceiling segments. This combined with the textures makes this part of the level have a purple color scheme instead of the final's blue. There are no booster pads or pathing routines, and the camera has a tendency to clip through the walls and floors as the player manually navigates it.
  • There are no death zones between the platforming sections.
  • After the first checkpoint, the lowest part of the room is visible when Sonic is up in the air. In the final, it just looks like a black abyss until the player navigates further in the level.
  • The springs after the first checkpoint usually send Sonic to the bottom of the stage, due to the moving platforms being broken.
  • To the right of these springs are a pipe and a platform that are not present in the final.
  • There are no camera angle changes as the player attempts to navigate the platforms in the second part of the level. The platforms themselves are also arranged differently than in the final.
  • The 1-Up after this platforming section is missing.
  • The camera breaks during the second tube run, not following behind Sonic and instead preferring to show the player the outside of the level geometry for this part of the stage.
  • Oddly, the center platform with the switch on it for the third part of this level is using the blue steel texture that is used for the tube runs in the final. In the final, this platform has a light blue texture instead.
  • The camera pulls out much farther from Sonic after he's pressed the switch, and starts this angle much earlier. It also stays at one angle during the animation, whereas in the final it has two.
  • No ambient voice clip plays when Sonic presses the switch. In the final, a computerized voice says "Final Egg Level 2 Isolation Wall Opened".
  • There is no elevator object leading to the final part of the act, though the camera changes are present. Sonic can just jump through the shaft to the next part of the level however.
  • The fan blades in the final part of the act and the glass enclosing them are completely missing, and the camera angle favors focusing on the center of the room instead of following Sonic. The area is as bare as the rest of the act - no enemies, spike balls, rings, or items.
  • The checkpoint before descending down to the bottomless pit area is missing.
  • Instead of having a few moving platforms, this version of the act's final part has many platforms forming a kind of staircase leading down to (and past) where you call the elevator. The camera angle while navigating these platforms is behind Sonic at an angle instead of directly behind him.
  • The elevator is not waiting to take Sonic to act 3, which makes this act yet again impossible to complete in normal play, though it is midway through the elevator shaft and can be reached by jumping down. The elevator repeatedly opens and closes its door when Sonic is close to it, even if he is standing on top of it. The elevator door has no collision, and nothing happens if Sonic manages to enter the elevator.
Sonic's Final Egg (Act 3)
  • The starting room is the starting room of the final without the elevator portion bolted on. Sonic starts at the back wall that the elevator dock would start at, with the camera facing the wall. There are no spike ball objects, items, or springs, though there are rings.
  • No ambient voice clip plays in the first part of the level. In the final, a computerized voice is repeatedly saying in the background: "Emergency! Emergency! Dispose of any intruders!"
  • All of the decorative objects are missing - spotlights, cameras, etc.. This includes the dolls Gamma targets in his version of the stage that make an appearance at the end of Sonic's.
  • Item capsules are missing from nearly every point in the level.
  • The camera is a little more broken during the first path, pulling farther away from Sonic as he goes down, which means the player can't really see him over the curvature of the floor. In the final it does a better job of following him (but still almost clips the floor geometry).
  • There are none of the Beats - the first room with them is completely bare in this version. The tubes they come out of are also not present in the walls.
  • The camera in the swarm room is very broken and tends to view the outside of the room's walls.
  • In the first swarm room, there are springs going up instead of a ladder. The wall closest to these is just flat geometry with none of the objects seen in the final.
  • Because there is no ladder, there is no platform that the ladder goes up to, and thus there are no floor spikes between the ladder platform and the floor.
  • The path leading out of this room has laser objects from Act 1 that aren't present in the final.
  • The path leading out of this room has fans embedded in its solid floor. In the final the entire path is just bare.
  • There is no checkpoint before the first fan room.
  • The fan arrangement in the first fan room is a continuous chain of fans. In the final it's a straight path of three fans, then a platform, then a crooked path of four fans.
  • There are no items or springs below the fans - if you fall, you die. In the final there is a spring below the second fan path and items next to the walls.
  • After the first fan room, there is an untextured duck enemy. It doesn't look like a badnik - it looks like a walking rubber duck, and it is much larger than Sonic and all of the other badniks in the game. It shoots projectiles at Sonic and then immediately runs away, and doesn't have walking or shooting animations - though if the player takes long enough to reach this room, it is already trying to run away into the nearest wall. When broken, it spawns a Chao Animal just like most enemies in the game, and it doesn't have a breaking animation. Its internal name is E_HIYOKO and it is referenced in the final - but when loaded, it's a copy of one of the Egg Keeper enemies and is identical in every way to them.
  • The entrance to the second fan room has sliding doors that aren't present in the final.
  • The camera in the second fan room doesn't follow directly behind Sonic like it does in the final. It also just cuts to a view of the next room when Sonic enters it instead of following him in.
  • The secret area with items that you reach via a ramp in the room has no items, but does have a switch of unknown purpose.
  • The third fan room is just a straight path of fans. In the final there is a conveyor belt and then a path of fans.
  • The camera in the third fan room doesn't follow directly behind Sonic and just cuts to a near-sideways view of him while the player navigates the fans.
  • The room and fan room after it are not in the final version of the level - the third fan room just goes to the second swarm room in the final. This extra room happens to be one of the only places in the level where item capsules were placed, and one of the few with enemies placed. The Spinners here are instead Electro Spinners as well.
  • The second swarm room has no Beats or the pipes that spawn them, like the first swarm room.
  • The second swarm room also has a platform on the upper level that does not exist in the final. This platform has a speed shoes box, a 10 ring box, and a 1-Up. In the final, the 10 ring box was removed and the speed shoes and 1-Up were moved to the pipes in the center of the room.
  • The path up has a booster pad like in the final, but no spring. The camera decides to clip out of the level geometry when the booster is used.
  • The second swarm room actually has item capsules placed near the exit out of it.
  • The pipe that Sonic is dropped into after taking the tunnel out of the swarm room is using completely different textures from the final. It is also missing a checkpoint.
  • The entrance to this pipe is covered up, though the player can still enter it.
  • The falling section present after the level's second checkpoint is entirely missing from this build. In this version, it's a pipe run spiraling downwards, like in parts of act 2. There are no objects, such as booster pads, present, nor any pathing.
  • This pipe section throws Sonic immediately into the third swarm room. In the final, Sonic falls through the falling section into one more fan room that that the player has to navigate, and then into a tunnel that launches him into the swarm room.
  • The third swarm room has two tunnel entrances. In the final there is just one.
  • The third swarm room has a ramp that leads to a dead end that isn't present in the final. The entire time you try to navigate this path, the camera has clipped out of the level geometry (again).
  • There are no massive sliding doors leading out to the next room like in the final.
  • The room after the third swarm room has fewer enemies (only the Spinners, no Egg Keepers). The Spinners are also Electro Spinners, unlike the final.
  • The fourth checkpoint is missing. The Egg Keeper that is to the right of it in the final is in its place.
  • There are no doll objects that pop up when Sonic passes them.
  • There is an unused robotic Sonic object referenced in this level that looks like it would've been an alternate doll model used with the doll objects mentioned above.
  • The final checkpoint is missing.
  • The final room has no enemies, platforms, or items. It is completely bare.
  • The arrangement of the beams between the final room and the end of the level is different - it makes an "X" shape that you go directly over with the Light Speed Dash. In the final, it makes two "X" shapes and you go between them with the Light Speed Dash.
  • No end of level sequence is triggered when Sonic reaches the platform - this means the player can navigate the tunnel to the right that leads straight to the Egg Viper (in the final this is done via a cutscene), though in this version it just leads out to the nothingness outside of the level geometry.
Amy's Final Egg
  • This is one of the levels demonstrated in the autodemo loop.
  • There is no opening cutscene of Zero dropping down behind Amy. As a result, the camera starts at a more distant shot of Amy as opposed to being directly in front of her like in the final.
  • Zero doesn't immediately notice Amy when the stage begins.
  • There are extra hint orbs here, such as the one at the beginning of the stage.
  • After the wall of lasers, there are no enemies and only one laser pod leading to the next area. There are also more rings. In the final, there are two Egg Keepers and three laser pods, and no rings.
  • There is no item box under the claw.
  • There is only a single laser object in the section where Zero breaks through the wall. In the final, there are two.
  • The hint orb in front of the elevator is missing.
  • The demo ends at the elevator section. Through hacking, additional parts of Amy's level can be seen:
    • The crates to the left of the "Choose a door" section are missing.
    • The large ledge near the end of the stage has a crate nearby that can be used to get high enough to reach the ledge with an ordinary jump.
  • The hint at the beginning of the demo is:
    • 敵にロックオンされても、逃げまわれば大丈夫。がんばって。("Even if the enemy locks on to you, you'll be fine if you just run around. Do your best.")


  • There is inexplicably some collision at the origin point in all three acts of Icecap. Spawning a character at the origin (such as playing as a character that doesn't have starting coordinates via hacking) causes them to stand on invisible but solid ground without them immediately falling to their deaths.
  • This level has no lighting, so everything appears to be ridiculously bright.
Sonic's Icecap (Act 1)
  • The level uses completely different textures throughout most of the level. In the final, the textures consist entirely of icy rock, while in this prototype certain parts of the level geometry have wood panel textures. The outdoor textures made up of photos Sonic Team took while doing research in South America are the same in this version however.
  • The ice crystals littered throughout the level have different models and textures.
  • There are no enemies or help orbs present in the room Sonic spawns in.
  • The tunnel leading outside has a bunch of the ice crystal objects placed within it (including seemingly clipping through the ceiling) and no booster pads until right at the exit. In the final, the tunnel just has the boost pads at the tunnel's entrance.
  • The boost pad at the end of the tunnel sends Sonic straight to a spring, which in turns bounces Sonic to a boost pad that sends him immediately to the spring leading to the next tunnel. In the final, Sonic is just sent flying out of the tunnel and has to navigate this outside area himself.
  • There are no numbered jump pads in the outdoor area.
  • The outdoor area has three enemies - an Ice Ball and two Boa Boas. The final has no enemies in this part of the stage.
  • The second indoor area doesn't have a help orb.
  • The spring leading up to the icicles was moved between this prototype and the final - in this version of the game it's position directly below the icicles and Sonic has to jump up to the platform that has it, while in the final the spring is positioned immediately at the end of the platform and is at an angle.
  • The icicles use different textures.
  • There are 10 icicles in this version - in the final, the two at the end were removed and a platform was added instead.
  • The middle icicle path to an item box has a much smaller platform here than in the final.
  • The surface on top of the icicle area has five rings here that are not present in the final.
  • The area after the icicles lacks the wooden railings seen in the final.
  • The path off to the right before the end of this area ends with a platform that has five rings, a wild card ring box, and a spring over a small hole, with some boxes next to the spring. In the final, this platform has four rings, fences at the edge of the platform, and the hole has been removed.
  • To the right of the spring mentioned above are three small platforms; in the final, boxes were added here and two of the platforms were removed.
  • The end of the second indoor area has the infamous bridge seen in pre-release screenshots. In the final, there is a rocket here instead, probably because the bridge object has a tendency to make Sonic fall through back to the bottom of the outdoor portion if he jumps while standing on it.
  • The tunnel leading to Act 2 has a checkpoint in front of it, and the platform that it's on is non-solid, making Sonic fall through after he passes the checkpoint. As a result, the level can't be completed through normal gameplay.
    • Like with Speed Highway above, the presence of a checkpoint before the beginning of the next act seems to imply that act transitions originally didn't act as checkpoints.
  • There are no wooden railing objects at the tunnel entrance leading to act 2.
Sonic's Icecap (Act 2)
  • This act cannot be accessed through normal means, but it can be loaded through hacking.
  • All of the texture changes mentioned above in the Act 1 section (the wood textures instead of rock, etc) are present here as well.
  • There is a spring floating out of bounds, where Big's portion of the level would be located.
  • The entrance from Act 2 is not blocked like it is in the final, and is just a hole in the geometry.
  • At the bottom of the stage, there are two Ice Balls. In the final, there is just a single Boa Boa here instead.
  • The spring at the bottom of the stage is missing the five rings in its launch path.
  • Under the ice at the bottom of the stage is leftovers for Big's Icecap, showing a different pool layout than what is in the final game. Instead of one giant pool with an underwater tunnel snaking off to access a hidden area, only the tunnel and a tiny unconnected pool to its left exist. The tunnel leads nowhere and abruptly ends.
  • Between the first and second springs is a misaligned line of five rings. In the final, this is instead a line of four rings and two spikes.
  • The first hanging icicles section is completely missing its spike clusters embedded nearby as well as the spring that would allow the player to skip the icicle section entirely.
  • The first hanging icicles section only has five icicles (the final has seven) and they are farther apart from each other. This section is also missing the spikes directly after them.
  • There no spikes near the line of rings after the first icicle section.
  • The section with a small gap the player has to jump over has a curved line of five rings, and has a hole that will make the player fall to the bottom of the cavern again if they miss it. In the final, a spring was added, the line of rings is now four instead of five, and a platform was added over the hole to prevent the player from falling.
  • The outcropping with the small icy pool has a switch here that does nothing (possibly for triggering an ice block object like the one used in the final), along with a line of three rings over the gap the player must jump. In the final, there is no switch here and the line of rings was changed to a large arrow of rings.
  • Under the aforementioned line of rings is a small area with a tiny platform that the player can use to get back to the icy pool outcropping. In the final, there are two springs here instead, one of them to get back to the outcropping and the other to progress.
  • The platform that the player jumps to in the section above lacks the 10 ring capsule that is seen in the final. There is also a small hole in the wall that is not present in the final.
  • The dash panel leading into the second icicle section is missing.
  • The area you can drop down to below the second icicle section is missing the circle of rings and the Ice Ball.
  • The second icicle section has six icicles (seven in the final) and is lacking the spike clusters embedded in the ceiling.
  • The section directly after the aforementioned icicle section is missing the two ring circles, and the spring is in a slightly different spot. However, the spring's ring path was never changed and is thus misaligned in the final.
  • The area where you cross the chasm with the ice blocks is missing everything except the switch used to toggle them, which is in a slightly different spot. Pressing the switch does nothing. In the final, the switch was moved to the left, a hint ball was added, and fences were added to the edge of the platform.
  • The checkpoint after the ice blocks section is missing.
  • The dash panels in the small loop are also missing.
  • The hint orb at the first jump panel used to open the entrance to Act 3 is also missing.
  • The boxes around the first jump panel are slightly different.
  • The jump panel sequence only has three panels; the final has four. The sequence here also has the ending spring-textured panel, seen in other stages.
  • Like the entrance to Act 2 in the previous act, the entrance to Act 3 here has no collision and will make the player fall through it. Because of this, Sonic's Act 3 cannot be accessed via normal gameplay.
Tails' Icecap (Act 3)
  • This is one of the levels demonstrated in the autodemo loop.
  • The camera angle when Tails escapes the avalanche is different - it is more of a slow pan like the camera shots for doing a trick off one of the ramps, whereas in the final it is much faster.
  • At the beginning of the level, the trees placed in the level are the dead-looking "beta trees" seen in pre-release screenshots of this stage, and then the snowy conifers show up halfway through (when the fighter jets appear). In the final, the conifers are used in all parts of the stage instead of these trees.
  • Directly after escaping the avalanche, there are three dash panels. In the final, there are two.
  • The area directly after escaping the avalanche has different object placement - there are no ice spikes directly after the trees, and instead there are a handful of the ice crystal models unique to this point in development. The placement is very bare and there are few objects.
  • After leaving the tunnel, the animated obstacle of massive chunks of ice is heard but not seen very well due to the object placement. The arrangement of the ice chunks in question is different compared to the final, leaning left instead of right, and looks like it was completely remodeled and reanimated for the final version.
  • There is only one icy structure you go through in that segment after the animated one, while in the final there are two of them.
  • The double trick ramp before the fighter jet section is actually two separate ramps in this prototype.
  • Doing a trick off the ramp gives you less height and distance than in the final.
  • The camera changes between doing a trick off a ramp and going back to the standard behind-the-back shot is much rougher than in the final.
  • There are no hot air balloons in the second part of this stage.
  • The demo ends before Tails reaches the final segment of the stage, so changes recorded in that are in Sonic's section below.
Sonic's Icecap (Act 3)
  • This act cannot be accessed through normal means, but it can be loaded through hacking, like with Sonic's other Icecap acts.
  • The gate the player has to break through in the beginning is facing the wrong way.
  • The level music starts immediately as the level is loaded. In the final, it starts when Sonic spots the avalanche behind him.
  • Sonic lacks a voice clip for spotting the avalanche.
  • When Sonic runs towards the snowboard, the camera follows him. In the final, the camera is locked on the snowboard.
  • The snowboard instantly appears under Sonic.
  • The underside of the snowboard has a different texture than in the final - it is predominantly blue and has a different design.
  • Sonic's snowboard sometimes incorrectly plays the icicle breaking sound.
  • The starting point of the snowboarding section lacks the giant boulders framing it, making it look more bare. It also makes it obvious that in the final, these objects are just placed on top of the existing wall, clipping through it, with no changes to shape the wall boundaries of the level around them.
  • The changes detailed in Tails' section above are also present here.
  • Sonic has a different audio clip when performing a trick.
  • The final cavern section has no rings.
  • The trick ramp to get onto the high path is a double ramp in this version. In the final, it is a single.
  • The high path has a dash panel and a line of rings that do not exist in the final.
  • The end of the stage is completely different:
    • The end capsule is not centered like it is in the final.
    • There are more trees lining the back of the area, and a log is to Sonic's upper left instead of to his extreme right.
    • The background geometry and scenery is all snowy mountains in this version. In the final, there are buildings and windmills, and large tree models.
Big's Icecap
  • This build has an extra camera file for this version of the stage, internally listed as Act 4. The filename (CAM0803S.BIN) has the S suffix that indicates that it is specifically for Sonic, and has a later date stamp than the camera file actually used for Big in this build; this is particularly interesting given that Big's Icecap is an altered version of Sonic's Act 2.
  • Sonic has his own object layout for this stage that is from a version later than this build - the objects are incorrect (for instance, numerous windmills placed on the ice) which indicates that this object layout is meant for an earlier object list, like in Knuckles' Speed Highway.
  • There are more Ice Balls.
  • Big cannot break the ice in any fashion (with boulders nor via jumping on it).
  • Big also cannot pick up the boulders.
  • As stated in Sonic's Act 2, there is an extra small pool here under one of the ice sections that is not present in the final.
  • The water is not animated and most of the underwater sections are not underwater (no drowning countdown and no water physics acting upon Big).
  • There are no spike cluster objects anywhere.
  • The small pool outcropping is missing the spring and speed shoes box.
  • The small pool in that outcropping is exactly the same as Sonic's in this version. In the final, it is an actual pool of water.
  • The small platform to the side of the area has a rock on it, instead of the two wild card ring boxes.
  • The higher areas of the level are completely empty, and are missing the springs, platforms, rings, and item boxes that are present the final.

Lost World

  • This level primarily differs from the original in object and enemy placement. There are few changes to the level geometry, though one of them is that the background walls for many of the areas are missing.
  • The level was compiled September meaning it's unplayable without extensive hacking.
Sonic's Lost World (Act 1)
  • The build has a blank camera file (CAM0700.BIN) for this act of the stage. This has a date of July 30, 1998. As such, the camera is yet again very broken, tending to show the outside of the level geometry instead of the level itself, or getting stuck in the floors.
  • The camera very jankily follows Sonic down when he falls into the stage. In the final it is much smoother.
  • The first room of the level has an open ceiling that is instead blocked off in the final.
  • There are two Boa Boas in the first room. In the final, there is only the one that is immediately seen when the level starts.
  • There are flaming arrows before the circular section.
  • There is a missing booster in the tunnel before the circular section.
  • The circular section has no rings to pick up within it.
  • The lines of rings in the tunnel after the circular section have crooked placement.
  • There is no item capsule in the air when Sonic leaves the second tunnel.
  • There are no platforms after the tunnel.
  • The first checkpoint is missing.
  • The camera has serious issues trying to handle the water serpent room, particularly when the player enters it.
  • There are no stone pillars in the middle of the water serpent room.
  • The exit to the room is already open: there are no colored switches to open the door, nor is there a display for them above the doorway.
  • To the right of the water serpent room entrance, there is a Boa Boa. In the final, there are just breakable stone boxes.
  • To the right of the water serpent room entrance, the large barrier/platform is misplaced - it is slightly floating above the floor. As a result, Sonic can walk under it.
  • The platform with the first switch is entirely missing. Instead there is a platform floating in the air that Sonic can't reach until the water level is raised.
  • There is a set of inverted spikes after the platform. In the final, there are floor spikes at this location.
  • There is another set of inverted spikes and a large L-shaped structure that leads nowhere. In the final, there is nothing here but a row of floor spikes.
  • Past the large L-shaped structure, there is just a stretch of bare floor. In the final, there are floor spikes, rings, and breakable box objects.
  • The platform that in the final would have the blue switch to open the exit instead has a water level switch in its place.
  • The camera tends to clip through platforms and other objects while Sonic rides the serpent.
  • The second water level switch in this version has a Leon guarding it. In the final, this particular switch has no enemies nearby.
  • There is an odd H-shaped platform directly in front of where the second water level switch is. It has no enemies or other items.
  • Sonic can just jump to the door with no trouble after the water level is raised a second time.
Sonic's Lost World (Act 2)
  • The camera has a tendency to kill the player often in this section.
  • The entrance before the mirror section has a gate object that continuously moves up and down. It has a tendency to push Sonic through the floor and kill him if he stands under it. In the final, there are two (completely solid) doors that open when Sonic gets close to them, and they have a more fleshed out opening animation.
  • Only the small, movable mirrors are present, and there are no large mirrors to guide them to. Because of this, there is no way to exit out of controlling one of the mirrors without restarting from a checkpoint from the pause menu.
  • Because the mirror puzzles can't be completed, the snake torches on the sides of the path cannot be lit.
  • The path directly after the first mirror is missing a Sol and the flaming arrows that come after it.
  • The path directly after the second mirror is missing a set of floor spikes between two platforms.
  • The path directly after the third mirror has a Boa Boa instead of a Sol. Of note is that in the final, this is still the case for Knuckles' object layout, hinting that his final object layout is a modified version of the one in this build.
  • The platform that has the fifth mirror inexplicably has a flame pillar object placed next to it in the water that's under the entire room.
  • The path directly after the fifth mirror is longer here than in the final: it has an extra platform with an extra mirror and the path continues on another platform placed at an angle from it. It has a Boa Boa and no flaming arrows. In the final, this is just a single long platform with flaming arrows, leading immediately to the trail of rings needed to continue.
  • The path of rings is a bit more crooked.
  • There are no rings on the water slide after the act's second checkpoint.
  • The three platforms between the sequence of springs at the bottom of the waterfall are missing entirely.
  • The entrance to the boulder chase is missing the door object that temporarily blocks it off in the final. There is another one of the moving gate objects directly after the checkpoint, despite it not being tall enough to accommodate the entrance without it visibly floating when it gets halfway through its animation.
  • There are no item capsules during the boulder chase.
  • The small pillar decorations on the ledge Sonic lands on directly after the boulder chase are placed (brokenly) at 45 degree angles inward. In the final, they are straight up and down.
  • There is another one of the moving gate objects at the entrance to the next hallway, and the end of the hallway is missing its door. In the final, both ends of the hallway have door objects.
  • The checkpoint in this hallway is missing.
  • The small hut at the beginning of the wall tile section has a pillar at the top of it that extends all the way to the ceiling. In the final, it lacks this pillar and also has a ray of light shining down on it.
  • The entrance directly into the wall tile room has another one of the moving gate objects.
  • The switches that move the wall tiles have lights shining up from them.
  • There are three switches placed on the ground floor on pillars of varying heights. In the final, there is the one on the ground, with the others placed in different (higher) places in the room. The placement in this version seems to hint that they were still debugging the tile puzzle.
  • All the enemies are Boa Boas - there are no Sols.
  • The panels start out in the connected positions needed to proceed.
  • The panels never light up and become walkable even when connected. As a result, this level cannot be completed via normal play.
  • The panels move in less random ways in this version, being relatively connected during every move.
  • A platform from what would be the second switch the player comes across in the final is missing here, though there is a very obvious gap in the wall tiling where it should be.
  • The path directly after the first rotating cube platform is a raised platform with floor spikes and a platform equal in elevation to the floor in the room ahead beside it. In the final, it is all just a flat platform with flaming pillars coming out of the walls beside it.
  • The checkpoint in this room is missing.
  • The room where the checkpoint would be only has Leons and a circle of rings. In the final, there are two Sols, some pillars, some breakable box objects, and an item capsule.
  • The final platform before the tunnel that leads to the exit has flaming pillars coming directly out of the walls. In the final, they come out of a thin ledge, which allows the player to hug the wall and jump over them.
  • The tunnel Sonic has to jump into has no rings leading into it.
  • There are no breakable box objects before the second jump down.
  • The switch that spawns the trail of rings to the exit is missing, which naturally means that the act is unable to be completed in normal play.
  • The platform that the switch would be on is just one single platform here, with a small pillar at each corner, behind a full row of floor spikes at the edge of the area. In the final, it's three platforms arranged, with two pillars that the rings would spawn between, and the floor spikes are just far to their respective sides.
  • The end of the level has no end capsule or trigger to end the level, adding yet another reason why the level cannot be completed in normal play.
  • The entrance to the mural room has no wall blocking it, so it leads into the void outside of the level geometry. The ceiling also has no collision.

Red Mountain

  • Red Mountain's texture files contain two unused greenish "ghost" textures.
Sonic's Red Mountain (Act 1)
  • The camera is very broken in this level - it has a tendency to take angles that make it hard to see what's ahead, clip through level geometry, clip through Sonic's model, and rapidly glitch out when springs are used.
  • There is no lighting in this act.
  • Sonic's spawn point is in midair over what his spawn point is in the final.
  • There are three Kikis on the crates at the beginning. In the final, one of them is instead on the ground to the left of the crates.
  • The ? ring box on a platform that you see taking the first rocket is replaced with a 10 ring box in the final.
  • Dropping down from the first hanging ladder is an area with a circle of seven rings, a Sol, and a rocket. In the final, the circle of rings was replaced instead with two squares of four rings.
  • The line of rings after the hanging ladder has five rings instead of the final's three.
  • Before the first checkpoint is a crate with two Kikis and a line of five rings. These enemies were removed and the line of rings only has three rings in the final.
  • The first checkpoint is placed slightly farther back in this build.
  • There is no hint orb at the first rocket that requires a switch.
  • The tower that the player can land on from this rocket is missing its spring.
  • After the small tunnel in this section, there is a Kiki alongside the Sol. In the final, just the Sol is here.
  • The ground after the tunnel has strange physics, making Sonic accelerate.
  • Under the collapsing platform near the second checkpoint is a spring that is not present in the final.
  • The bridge objects in this level have green railings instead of brown and their bodies are bright red, made more garish by the lack of lighting in this act. They also lack poles to attach their railings to, so they look like they're floating in midair.
  • The area across the bridge is lacking two of its spike balls and there is some extra fencing to the right.
  • The top of the mountain after the second checkpoint is missing its spring and item boxes.
  • The area at the first zipline station has a Sol that is not present in the final, and the platforms at the back of the mountain are arranged slightly differently.
  • The zipline station's animation loop is much faster than in the final.
  • There is no item box along the zipline path.
  • When Sonic takes the first zipline, the camera is positioned in front of him, and also clips through level geometry while following him. In the final, it is behind him, like a sane camera. The cut to a side shot of Sonic before he lands is still present here, however.
  • The end of this zipline segment has Spinners that are not present in the final, and the item box that is after the spring is missing.
  • The object layout after the first collapsing bridge segment is different:
    • The Spinners are on the ground. In the final, they are arranged in the air to be a homing attack path.
    • There are two platforms: one with a spring pointing to the second platform. In the final, there are three platforms that are arranged as such so the player has to do platforming; the first of these has a 1-up and the spring is gone. The third platform in the final is the same as the second platform in his build.
    • The ground is missing two dead tree objects, and the fences are set farther away from the edge of the geometry.
  • The area leading up to the rocket in this section has four extra crates and an extra Kiki, with an extra 10-ring box. In the final, there is just one box and one Kiki here.
  • Close to the rocket are two crates and a lava geyser. In the final, this is instead a skull flamethrower object and a 1-up.
  • There is a jump pad before the segment where you have to vertically climb a sequence of seesaws. In the final, there's a hint orb here instead.
  • The distance the three springs in the portion of the level near the end, where you have to hit a switch that's under one of the hammer obstacles to get a rocket, is off and will send Sonic past the metal flooring he needs to land on.
  • There is no ring capsule in the air when you're using these springs.
  • The last checkpoint of the act is missing.
  • There is no extra life before where the act's final checkpoint would be.
  • There is no Kiki before the bars during the last part of the act.
  • One of the sets of bars (the third one, in the middle) is missing, but there are rings on the rock below it that are not present in the final. As a result, the player has to use a homing attack or a long jump to get to the next set.
  • All the bars in this portion are missing rings below them.
  • The player can walk on the sides of the top of the mountain in this version. In the final, there is an invisible wall preventing this.
  • Before the act's final zipline, there are firebreathing skull objects. In the final, there are just rings at this location. The Spinners found here in the final are also missing.
  • There is no ring capsule during the act's final zipline ride.
  • The transition to Act 2 is rough and buggy - the game cuts to Sonic falling into Act 2's layout before he enters the trapdoor entrance, and the camera when he enters Act 2 is outside of the level's geometry, making it impossible to see him.
Sonic's Red Mountain (Act 2)
  • Like with Act 1, the camera in this stage is immensely broken and favors showing the outside of the level geometry instead of the level itself.
  • If the player enters Act 2 via normal means (via Act 1), the lighting will still be missing. If the player dies or enters via the level select, the lighting will be loaded in.
  • Instead of Sonic falling a short distance to the floor like in the final, he falls all the way from the top of the entrance.
  • The camera is much closer to Sonic when he hits the checkpoint. The checkpoint is also closer to the entrance's back wall.
  • There is no shield capsule before the first set of Spinners.
  • In the section where Sonic can run on the wall, there is a 1-up on a rock to the left that is not present in the final.
  • After the Spinners and Kikis, there is a vertical chunk of rock that is not present in the final. Instead, it's a flat outcropping in the final game.
  • The lava rising timing is off during this part of the stage - it will start rising before hitting the large area with the lava geysers; when the player reaches the act's second checkpoint, the lava has risen enough to almost overtake the platform the checkpoint is on. In the final there isn't a cue for the lava to rise at this part.
  • The camera completely breaks when Sonic uses the springs after the act's second checkpoint.
  • The lava does not rise to overtake the ground under the rock platforms that fall over until after Sonic has passed that section.
  • There are no enemies near the rock platforms, making them much harder to traverse in this version of the level.
  • There is a spring after the rock platforms. Unfortunately, this area is usually covered in lava, so the player never sees it...but the homing attack can select it, which naturally means that the player will get hurt by the lava in the process.
  • The animation loop for the machine in the background during the second platforming section is much faster.
  • The large platform has a large crate arrangement and a few Kikis on it - in the final there are only a few crates and a couple of Sols.
  • The 10 ring box behind the crates is moved to the right and is instead a ? ring box in the final.
  • There are two Sols on the platform next to the cells - in the final there is only one.
  • There is no light booster shortcut to the end of the level at the beginning of the final platforming section.
  • In the level's final platforming section, there are two Spinners not present in the final. The line of rings near the collapsing platforms are also missing, and another line of rings close by has five rings instead of the final's three.
  • There is inexplicably a crate breathing fire (likely a crate that was placed over a firebreathing skull object). In the final, there is a spike ball here instead.
  • A line of rings interects with the dash panels that throw the player into the air. In the final, these are moved farther forward for this reason.
  • There is no ring capsule when Sonic is thrown into the air by the dash panels.
  • Before the final hallway to the end of the stage, there are two ? ring boxes missing where a 10 ring box currently is.
  • The gauntlets of firebreathing skull objects after the final checkpoint have none that are positioned above ground level - which means that the player can basically just homing attack over them.
  • The top of the cavern at the end of the level lacks a texture (appearing as completely white), as do the decorative spider creatures (who also appear as completely white).
  • The end of the level where the end capsule is doesn't completely transition from indoor assets to outdoor assets - as a result, the earlier parts of the level (or rather, just the lava due to draw distance) are visible when Sonic is falling down to the capsule due to the lack of the white fog and the skybox looks completely black. When the camera is angled upward at Sonic after he opens the end capsule, however, the outdoor skybox and white fog is visible (before vanishing again when the camera angles downwards while waiting for the game to perform a nonexistent score tally).
Knuckles' Red Mountain
  • This level is actually the version from the TGS build of the game. It has an in-level tutorial for how Knuckles plays and contains a lot of hint balls, and the emerald shards are always in the same places. These locations are:
    • Directly in front of the initial spawn point;
    • Underground at the area Sonic lands after using the jump panels;
    • Near the falling spike ball in the area just after Sonic's first zipline sequence.
  • The starting area has three rings. In the final, there are six rings and a hint ball.
  • In front of the starting area is a floating line of four rings. In the final, this is a 10 ring box.
  • At the line of Spinners near the starting area, there is a hint ball that is not present in the final.
  • This line of Spinners has four of them. In the final this is a line of three.
  • There are three hint balls near the shard at the starting point:
    • One is next to the shard;
    • One is on the bridge;
    • One is on the other side of the bridge. This one actually got moved to Knuckles' Speed Highway in the final.
  • On the top of a mountain behind the starting point is another hint ball that is not present in the final.
  • To the right of the starting point is a tall mountain that has two spike balls and a hint ball on top of it. In the final, it is three spike balls in a triangluar formation and a 10-ring box instead.
  • A line of rings on the path to the rocket at the bottom of the mountain are not present in the final.
  • The rocket that needs to be activated by a switch in Sonic's version of the level still has to be activated here too. In the final, the rocket is already activated and the switch itself is replaced by a square of four rings.
  • Knuckles' respawn point after a restart is the location of the first shard. In the final, his original spawn point is used instead.
  • A 10 ring box and an invincibility box are missing on the side of the mountain below the area with the rocket.
  • At the top of the mountain are three hint balls. In the final, one was removed, and the other two are in different locations.
  • The zipline platform is empty in this version. In the final, there is a Kiki and a circle of rings.
  • A 10 ring box opposite the seesaw platforms is missing.
  • Underneath the collapsing platform after the first ziplne section is a firebreathing skull that is not present in the final.
  • A Spinner was moved from over a pit to near the collapsing platform section. They also got changed from three enemies to one.
  • Near this area, a Kiki was replaced by a Sol in the final.
  • Tikal's hints exclusive to this build are:
    • 困った時は私を探してみて。(If you are confused, try to look for me.)
    • L.Rボタンで カメラをまわすことができるわよ (You can rotate the camera with the L and R buttons)
E-102 Gamma's Red Mountain
  • This is one of the levels demonstrated in the autodemo loop.
  • The wall at the beginning of the level has three targets. In the final, there are four.
  • There are no Kikis on ledges like there are in the final - the enemy placement is more bare.
  • There are no decorative spider objects hanging from the alcove the extra life is in.
  • At the first fork, there are fences and fire traps that are not present in the final.
  • There is no shield box after the forked path.
  • There are no enemies or objects before Gamma enters the room with the sideways ramp path. In the final, there are a few of those bat enemies and a shield.
  • Gamma seems to "stick" more to the sideways ramp path than in the final.
  • The four Spinners after the sideways ramp room are in a slightly different arrangement.
  • The wall leading into the next open area has two targets. In the final, there are three.
  • When Gamma enters the first gigantic room of the stage, the camera just cuts to a sideways position. In the final, it follows behind Gamma into the room and zooms out.
  • The first set of enemies in this room has no item boxes with them.
  • The platform to the right has lava geyser objects and is impassable, and is also shorter than in the final. In the final, there are two Kikis and it is a flat space.
  • The item box on said platform is up front. In the final it is pushed back, behind the two Kikis.
  • The gigantic rock arch and the checkpoint are set up past the platform here. In the final, they are more adjacent to it, probably because the platform is larger than in the prototype.
  • The camera just cuts to a higher shot of Gamma after going through the checkpoint. In the final, the camera is still following Gamma around behind him.
  • The layout is made entirely of black rock after the checkpoint. In the final, the walkable ground transitions from the black rock to some brown rock.
  • There is a hint ball before the level's boss.
  • E-104's boss fight is largely intact (see above, in the Bosses section).
  • Tikal's hints in this level are:
    • どこかに隠れた通路があるはず。 探してみて。(There should be a hidden passageway somewhere. Try looking for it.)
    • ダイナマイトを壊せば 先に進めるわよ (If you destroy the dynamite you can continue on ahead)
    • These are not present in this level in the final, due to Red Mountain being a mid-story level for Gamma in the final game.

Windy Valley

The Windy Valley in this build is actually the original version of this level seen in many pre-release screenshots and footage. At the time of this build, it is already scrapped: it is missing (most) textures, music, and unique sound effects, and no effort has been made by the developers to make it remotely functional within the game itself. It cannot be loaded in-game normally due to expecting a completely different version of 1ST_READ.bin - the game will jump to an invalid pointer (of which there are many) and crash, and the stage files themselves refer to numerous items that either have been moved or do not exist. The game doesn't even have an entry for it in the list of level textures - the list skips from Emerald Coast to Twinkle Park.

However, through intense hacking of the level's pointers and memory locations, large swaths of it can be restored - its objects, object programming, and event programming are all intact but are buried in locations different from the 1ST_READ.bin in this build.

  • The object set file in this build was last modified 7/28/1998 (while the level file itself has a 9/24/1998 modification date) - as this build's date is 10/16/1998, this is one of the oldest files in the entire build.
  • The number of objects this version of the level has is 115; the final has 79. Many of these objects were scrapped or replaced with newer versions in the final version of the game. General objects include:
    • Small decorative items, such as: bushes, flowers, rocks, broken pillars, etc.. Many of these are animated, and most of them lack collision (likely intentional, to keep the player from stopping every time they'd run into them, which would be often).
    • An older version of the trampoline object seen in the final. It is smaller than its final counterpart, and the game crashes when Sonic uses it due to the game calling for a unique animation (as seen in the final game) that isn't in the build when he bounces on it.
    • Animated spinning propeller objects. Some of these were used in the final; all of these items in this build are animated to spin much faster than in the final game.
    • Hovering platform objects (O_RAFT). These objects are animated and have collision, though they're a bit buggy - while they hover up and down, the player still stays in the same spot in the air, clipping through their surfaces.
    • A more sophisticated version of the PuWind object that exists in the final. In the final version of the game, this object basically makes the character hover up and down (you also see this in Sonic's Final Egg, with the fans), but the version of the object used in this level makes the character slowly rise upwards, with leaves alongside them. The object itself also stays attached to the player while in mid-air, and even while walking away. This basically acts as a way to keep the player from dying if they fall into one of the stage's many pits. However, it is very taxing on the game's performance, which is likely one of the reasons why it was scrapped.
    • A floating particle object, Tanpopo, which exists in the final build but has a different visual effect than the one used here.
    • Baneiwa ("Spring Rock") - these are floating blue spring objects unique to this version of Windy Valley. Unlike the springs actually used in the game, in which the player just has to touch them to be thrown, the player has to actively jump on top of them to have anything happen.
  • The game also has objects for this stage that are unreferenced (models and code existing in the build but don't have names or anything pointing to them):
    • Pillars that are used for static scenery. They are very rough but all have the same subroutine attached to them.
  • The game also has objects that are unused (referenced by the stage's object list but are not placed in the level):
    • bleaf, an object that spits out leaves that fall down in a zig-zap pattern when the player walks near it. The angle at which they spawn is based on the direction the player is facing when they walk towards it.
    • An upright spinning propeller object that has no collision;
    • A couple of decorative grass objects;
    • A sign post;
    • A pole with small spinning propeller objects on it, much like the used ones that mark invisible wind paths in Act 3;
    • Dai7, a rock object. The other objects like this are actually used in act 1, perhaps this one just got missed?
    • TakoW, a net/mesh-like object. It has no collision, but looks like it at one point might've been used to catch the player.
    • Dome2 and Dome3, propeller objects similar to a used one;
    • Prop1, a large floating propeller object similar to a used one in Act 3;
    • PropeB, two horizonal rows of propellers. PropeC, which is a similar object, is used in Act 3.
    • IwaB, another unused rock object.
    • Wele, an elevator booth platform. It has a propeller on top and a propeller at the bottom and is capsule-shaped, and is not large enough to fit Big or Gamma in it. When approached, it will move straight down and disappear (and clip through anything in its path), then respawn when you leave the area and come back to where it initially was.
  • Some of the springs placed, especially in Act 1, clip through nearby walls and objects. This indicates that at the time this level was made, a different and smaller spring model was being used.
  • The level file has a larger file size than the final version.
  • There are only level object files for Sonic, but there are initial coordinates for Sonic, Tails, and Gamma, who all visit Windy Valley in the final. Sonic has coordinates for all three acts and Tails has coordinates for only Act 3, like in the final - however, Gamma has coordinates for all three acts despite only visiting Act 1 in the final game. Gamma's initial coordinates values are the same as Sonic's, so he starts in the exact same places.
  • Despite the above, E-103 Delta's model is included in STG02.BIN, indicating that some work on Gamma's version of the level was made.
Act 1
  • Contains level geometry, a Sonic Only level object file, and a CAM file for the camera system. The CAM file in practice yields rather strange behavior, because it is actually made for a much older version of the game. While this build only lacks a few camera types that are in the final, this CAM file was made during a time in which very few types existed.
  • This act contains a massive amount of objects - around 1800. The limit to the number of objects the game will load is 1023, which indicates that this level was made before this limit was put in place. Because of the large number of objects, the game will run rather slowly in this stage.
  • The level loads three enemies, but only uses two - the chameleon badnik is not placed anywhere in the level.
  • There are no starting position coordinates for Amy or Big despite them appearing in pre-release footage of this level.
  • This level has three bridge objects, but their model is entirely missing. Their collision and coding however still exist and they can be walked on if hacked into the game.
  • The twister model seen in pre-release footage of this stage still remains in the game, though it has to be hacked in to function. The event that spawns it is still present in the build (causing the tornado to spawn in, move out of the opening in the level wall, and start sucking things up), as is its dust cloud texture, which somehow still survives in the build! Over time, it will start ripping apart pieces of the level geometry and getting closer and closer to the player. However, the game will crash when the player enters due to the stage attempting to load act 2.
  • The tornado itself is not referenced at all in this stage's set file. Instead, it is loaded in through a function call in 1ST_READ, unlike virtually every other object in the game.
Act 2 - Tornado
  • Windy Valley's level table's pointer to Act 2 is NULL, and its land table is completely missing. There are level models present however, as well as initial coordinates.
  • There is data for the tornado "enclosure" that wraps around the level proper, along with subroutines to load it.
  • Unlike Act 1, it completely lacks CAM data.
  • This act has some objects that do not appear in the final:
    • T_Raft1, a very small platform with collision that can be made to hover up and down if the right parameters are passed to it;
    • T-Raft2, a half-pipe-shaped platform that has programming to quickly float up and down. It is hard for the player to stay on it as a result.
    • TSpring, which is entirely missing its model. It has no model data in the stage file, and instead has three pointers associated with it in 1ST_READ. These pointers are unique to Windy Valley. It is programmed to launch the player into the air like a normal spring, and functions as such when hacked into the game.
    • Lauchin, a unique spring object. It is a rather small, flat object that sends the player flying straight up in the air. It actually has a coil design and retracts slowly when the player lands on the ground.
Act 3
  • Contains level geometry and a Sonic Only level object file.
  • Tails has initial coordinates for this act, and there is P2PATH data for racing Sonic.
  • Like Act 2, it completely lacks CAM data. As a result, the camera when the level is loaded in the autodemo zooms farther and farther away from the player the longer they proceed through the stage.
  • The propeller springs seen in early promo footage of this act still exist in the build. These springs aren't as sensitive to the player's collision as normal springs, but sends the player flying much faster.

Sky Deck

  • Appears to be largely intact and nearly identical to the final, but can't be loaded without intensive hacking due to it being compiled in September, which means it's expecting a different version of 1ST_READ.bin.
Act 1
  • Act 1's lighting files are present, but seem identical to the final.
Act 2
  • The level geometry, while very close to the final, has a few alterations, particularly in the final area of the act. The area where you have to fire rockets at the large cannon is missing its two rocket platforms, which indicates that part of the level was a late addition.
  • The textures are slightly different, particularly for decorative parts of the stage geometry the player would be hard-pressed to see in normal gameplay.
Act 3
  • The level geometry, while very close to the final, has a few alterations:
    • The offshoots in the latter part of the stage (where Knuckles can enter to find shards) have shorter hallways in this version.
    • This version has symmetrical tube structures in the first part of the stage, over the first area the player lands in after ascending from the beginning of the act. In the final, one of these is missing.
    • There is only one set of lattices bordering the stage geometry in this version. In the final, this is doubled.
    • The textures for the square-shaped holes that Knuckles can dig into in his version of the act are far darker than in the final.
    • Object OCARRIER3 is used in this build.

Hot Shelter

  • Is completely missing in this build - no level data whatsoever, aside from initial coordinates for Amy.


Sand Hill

  • This build has a single camera file (CAMSBOARDS.BIN, with the S suffix for Sonic) for Sonic's minigame. In the final, two camera files are used instead.
  • This build also has a single set file (SETSBOARDS.BIN, with the S suffix for Sonic), which is smaller than its corresponding final. In the final game, there are two set files - one for Sonic, one for Tails.

Sky Chase

  • Sky Chase only has one level slot in this build - in the final, there are two Sky Chase levels.
  • Sky Chase's files expect a different version of 1ST_READ.bin, and thus cannot be loaded without extensive hacking.
  • There is a camera file for this stage (CAMSHTS.BIN) that is unused and blank; the build contains the camera files for both used acts of Sky Chase and are identical to the final, so the existence of this single, blank file indicates that the game used to use only one camera file for Sky Chase.
  • There is also a single set file in this build for Sky Chase - in the final, there are two: one for act 1, one for act 2.
  • There is no path data (used to make the levels "on rails") included in this build.
  • The game has texture references for three acts (0/1/2), and three object set files.
  • Act 1 only has "HODAI" enemies in this version - in the final there are other enemy types.
  • Act 2 in this version uses the exact same object placement as Act 1.
  • Act 3 doesn't correspond at all to any final version, because there are only two acts in the final. This object list makes reference to a bunch of everyday household objects - TVs, chairs, sofas, etc.. These can be seen in a preview build of SADX, but there are more types of these objects in this build. The object list also references BOSS, the infamous unused "dragon", which also has a model in this build.

Twinkle Circuit

  • Only level geometry (an early model, like Casinopolis above) is present, and it occupies the slot that Mystic Ruins - The Past occupies in the final. The geometry has small inclined areas that aren't seen anywhere in the final in any course.


  • None of the characters have their appropriate upgrades in any of the in-game cutscenes, except for Gamma occasionally having the Jet Booster (see below).
  • The cutscene where Eggman ambushes Sonic and Tails (Tails version) has several differences:
    • Tails' theme is the backing track for the entire cutscene. In the final, the theme playing in the background is Eggman's.
    • The cutscene takes place at sunset. In the final, it takes place at night.
    • Tails's mouth is modeled differently in his closeup after being gassed by Eggman.
  • The cutscene where Amy first meets E-102 Gamma in the Egg Carrier has several differences:
    • There are item boxes in one of the other cells. In the final, there are no item boxes and a black Chao egg is contained in one of the cells.
    • When Gamma first appears, he is in his normal standing pose. In the final, he is in the "gun held" pose that he has on the character select screen. Because of this, in this prototype his animation momentarily glitches when beginning to turn to his right - he briefly takes on the "gun held" pose before turning.
    • There isn't any odd draw-distance fog in this version, and the lighting is much brighter here.
    • The game can't seem to decide if Gamma has the Jet Booster or not. At the beginning of the scene, he has it, then it disappears when walking to the cell, reappears while he questions Amy, and disappears while glitching out.
    • Likewise, the game can't seem to decide if Gamma has his targeting laser or not. It seems to be tied to the appearance of his Jet Booster, as it disappears when that item disappears.
    • When Amy starts imploring him to help, he backs up. However, his animation in this prototype is actually much smoother than in the final - he moves back more with his backing up animation. In the final, he is inexplicably forced back and then does his backing up animation.
    • Gamma's "glitching out" noises are much louder than his voice.
  • In the cutscene where Amy meets Sonic outside of Casinopolis, the bird's wings are missing.
  • The cutscene where Eggman addresses all the E-100 series has several differences:
    • The lighting is much brighter. This causes issues with the rendering of the E-100 series, primarily faces that appear white due to the lighting.
    • In the final, there are green lights at the corners of the monitors behind Eggman. These are missing here.
  • The cutscene where Gamma steals Froggy from Big at Emerald Coast has several differences:
    • "BIG Fishes at Emerald Coast" is playing in the background. In the final, there is no music.
    • Gamma inexplicably has his Jet Booster upgrade.
    • Big's shaking animation goes on for much shorter here - he shakes and then immediately turns around to face Gamma. In the final he shakes for about a second before turning around.
    • Gamma's idle animation is slower in this scene than in the final.


  • The noises the Chao make are a bit unfinished, being mixed louder and are more robotic than in the final.
  • Chao make the "playing with animal noise" as an ambient sound (like how Chao have ambient noises in Sonic Adventure 2). In the final, Chao make no noises unless they are actively doing something, such as eating, being thrown or hurt by the player character, or playing with an animal.
  • Chao constantly emote in this build, often randomly having exclamation mark or heart emotes while running around. In the final, Chao only emote when actively doing something, such as eating, being thrown or hurt by the player character, or playing with an animal.
  • Chao will stay still until the player approaches them, upon which they will start constantly follow the player around. In the final, they do things on their own and aren't as needy.
  • Chao do not swim and do not have a swimming state - they will run around underwater as if they are on land.
  • When a Chao is hurt, they show a emote that is present but unused in the final, being just a messy jumble. In the final, it's a tornado-like swirl.
  • If the player hurts a Chao, they might briefly run away from them, a behavior not seen at all in the final.
  • Chao cannot die from being mistreated, unlike in the final.
  • When thrown, a Chao will slide for a while, a behavior not seen in the final at all.
  • Chao instantly change form when given a single animal to play with - in the final it takes many to do so, as the change is more gradual and based on a Chao's best stats. This, combined with the animal spawning mentioned below, seems to imply that Chao were undergoing a bit of testing in this build.
  • The individual changes a Chao undertakes when given an animal are different from the final - for instance, a Chao given a Lion in this build will have them turn green with horns like the adult Running Chao, whereas in the final, a Chao given a Lion would turn red with different horns, because a Lion is a Strength-based animal.
  • Chao do not take on adult forms in this build; instead, the limit implemented in the final for their changes as a child are not in place, giving them vastly different appearances over time. Also as a result of never aging, they cannot be bred.
  • If a Chao is in the middle of an action when being picked up by a character, they will stay in that frame of animation while held. For example, if a Chao is in the middle of tripping and the player picks them up, the character will be holding the Chao in the tripping pose. In the final, Chao are always in a sitting pose when being held by characters.
  • The baby Chao in this build start out walking. In the final, they crawl until their Run stat gets high enough to allow them to walk.
  • Coconuts don't fall from trees when shaken.

Chao Gardens

Station Square (AL_GARDEN00)
  • This Chao garden, as well the Chao spawned in it, is seen in some early screencaps.
  • It is largely intact and can be loaded through the level select without crashing the game.
  • The player spawns one of each of the following animals: Rabbit, Deer, Kangaraoo, Elephant, Lion, Gorilla, Mole, Koala, and Penguin. Of note, the Flying type animals (Parrot, Swallow, Peacock) and two of the Swimming animals (Otter and Seal) are not spawned.
  • Eight Chao (the maximum number in a single garden in the final) spawn in set positions.
  • Character controls are disabled here without hacking.
  • The camera is closer to the player and cannot have its zoom changed.
  • The entrance to the Chao Race doesn't exist - it's just a hallway with no doors or features. Walking through this hallway triggers no event.
  • The exit from the Chao Garden doesn't exist - it's just a square cut out of the geometry leading into a black void, with no elevator doors. The player can jump into this void and die. Chao can also be thrown into this void.
  • There are no teleporters to the other Chao gardens.
  • There are no floating help monitors.
  • The VMU machine always says NO DATA on it. It takes Chao...but they can never been taken out. The "OK!" animation flashes on its screen but it doesn't create a save, and stepping on the button again to try to get the Chao back does nothing.
  • The VMU machine takes more than one Chao. In the final, only one Chao can be taken on a Chao Adventure.
  • The trees do not drop nuts.
  • The collision detection in the corner pillars is completely broken - Chao and the player character will clip right through them.
  • The corner pillars are positioned improperly, hovering off of the floor a little bit and its edges clipping into the level's walls.
  • The ceiling has no collision detection - Tails and Knuckles can just clip right through it.
Egg Carrier (AL_GARDEN01)
  • The Egg Carrier Chao Garden is actually the floating island seen in very early video and pre-release screenshots of Chao. Its geometry is an island cut out of the old Windy Valley Act 3 geometry (see above) with several decorative structures removed (fallen pillars, fountain etc). All of the textures it makes reference to are the same ones referenced in that stage, which unfortunately means that it points to textures that don't exist in this build. Its object list points to rings, a tree, and a flower.
  • It can't be loaded in-game without its stage file being edited due to expecting a different version of 1ST_READ.bin.
Mystic Ruins (AL_GARDEN02)
  • The Mystic Ruins Chao Garden has level geometry and not much else - it has no reference to textures whatsoever and only has rings in its object list.
  • It can't be loaded in-game without its stage file being edited due to expecting a different version of 1ST_READ.bin.
  • Its geometry is an early model compared to the final (like with Casinopolis above) and has several differences:
    • The entire area is much smaller than in the final.
    • The entrance is a rectangular cut out for a door instead of the tunnel-like minecart track exit of the final.
    • The entrance is to the left of the pool instead of to the right.
    • Because of the entrance's location, the raised portions of the layout present in the final are missing here.
    • There are no pillars or ruins present, unlike in the final.
    • The pool is a half-circle, like the cliff the level is built into cuts it off. In the final, it's a small full circle.

Chao Racing

  • The only level file in this build that exists for Chao Racing is AL_RACE.bin. Only level geometry for the stage is present - there are no textures or objects. The course structure is the same as the final, but the geometry has a few differences:
    • The area where the races start has no hills surrounding it. There is also a large wall to the left that is not present in the final.
    • The third platform that the Chao get to in the Amethyst Course is floating. In the final, it is attached to the ground.
    • The bridge connecting the second and third platforms is an ordinary bridge. In the final, it is a bridge made of large blocks.
    • The arch over the path under the Amethyst Course's finish line is wider, and missing the water that flows through it in the final.
    • The island at the start of the Ruby Course is missing.
    • The end of the course has an arch over it that is not present in the final.
  • The build does have a camera file (CAMAL_RACES.BIN). The final uses two camera files instead of the single one found here.
  • The build also has a set file (SETAL_RACES.BIN). The final uses two set files instead of the single one found here.
  • The Chao Stadium level used to set up Chao races is missing from this build.


  • The title screen used in this build has its own filename, DEMO_TITLE.PRS.
  • This build has three text files contained within track01.raw. The three text files are:
    • SONICABS.TXT: Containing "Abstracted by none."
    • SONICBIB.TXT: Containing "Bibliographiced by none."
    • The build has a number of decompressed event files (EVF0800.BIN through EVF0806.BIN); in the final, these are compressed and given different names in the final. EVF0803.BIN is missing, and likely corresponds to a demo for Knuckles as it is also missing in this build.


The hidden wallpaper.
  • Inside track01.iso, there is a folder called EXTRA. Inside the folder is a .bmp wallpaper that was on the Japanese website.

Unused and Leftovers

  • TITLE.PRS is in this build too, but unlike in the final (which shows a title screen for a "beta" labeled version), it shows the TGS '98 version of the title screen!
  • There are unused textures dating back to 1997 saying "GOAL!!" (GOAL_A.PVR, GOAL_B.PVR) and "START!!" (START_A.PVR, START_B.PVR).
  • There are unused graphics that were likely used for mission rankings, like in Sonic Adventure 2. They exist in the final's files as well.
  • An earlier version of the pause screen is included in this build, including assets, but can only be seen in-game via hacking. Only the textures from this survive in the final.
  • Textures for the font used in boss title cards is in a file named 32ASCII.PVR. This file does not exist in the final; the font was moved to another location, likely to texture files for stage objects. The font itself saw some alterations between this build and the final:
    • Q was replaced with the symbol for Delta;
    • X was replaced with the symbol for Epsilon;
    • q was replaced with the symbol for Zeta;
    • x was replaced with the symbol for Alpha (used to designate Zero, which in supplemental material is referred to as E-100 Alpha);
    • The symbol for II (Roman numeral 2) was added at the end of the final font file;
    • The symbol for Beta and the kanji for "revised" (改), both used for E-101 Beta Mk II in the Japanese version of the game, were added to the JP version of the final font file.
  • Likewise, this build has a separate texture for the boss fight HP bar (TARGET_HP.PVR) that doesn't exist in the final; it was likely merged into another set of files instead of being a standalone item.
  • CAM0B00S.BIN is an empty camera file for a cut stage or test stage. Unlike all the other camera and set files in the build, this one uses hexadecimal numbering instead of decimal numbering. It also has the same file date as the camera file used for the test stage (see above), which is also blank. On the other hand, if the filename is read as decimal, it'd be CAM1100S.BIN - this could indicate that it could be for a cut stage, as all versions of the game skip STG11 in their numbering schemes.
  • DROP.PRS is an unused water drop animation.
  • RIPPLE.PRS is an unused water ripple animation, circular and looking like it could go with DROP.PRS. It might be used in the Chaos 0 fight for the rain drops hitting the ground.

Physical scans

Dreamcast, JP
SA AutoDemo BackCover.pngSA AutoDemo Cover.png
SA AutoDemo Disc.png

External links

Sonic Adventure
Sonic Adventure title.png

Main page (SADX)
Cheat codes (SADX)
Credits (SADX)

Manuals (SADX)
Promotional material (SADX)
Magazine articles (SADX)

Development (SADX)
Hidden content (SADX)
Hacking guide