Sonic Delta

From Sonic Retro

Sonic Delta
Version: v0.78 - v0.79Beta
Last release: 2023-10-23
Status: Active
System: Sega Mega Drive
Original game: Sonic the Hedgehog 3 & Knuckles
Credits: Esrael

Sonic Delta Origins is a groundbreaking ROM hack by famed Sonic scene member Esrael Neto, which combines Sonic the Hedgehog, Sonic the Hedgehog 2, and Sonic the Hedgehog 3 & Knuckles with some prototype elements restored.

The main version of this hack was formerly titled Sonic 2 Delta and was based upon the Simon Wai prototype; version 0.24 transferred the codebase to ‘revision 2’ of Sonic 2 from Sonic Compilation, and version 0.29 moved to the Sonic the Hedgehog 3 & Knuckles codebase, shortly followed by a name change to Sonic Delta 40 Mb.

Zone-Specific Content

Many changes have been made to various zones, mostly implementing cut content from prototypes of the Genesis games. Such changes are listed here, in zone order:

  • Green Hill Zone: The Sunflower now uses a similar palette to the other flower, a small section is added to the end of the first act, with many loops and speed boosters.
  • Marble Zone: UFOs from the Sonic 1 prototype appear in the background.
  • Labyrinth Zone: Uses the prototype background and decorative elements.
  • Scrap Brain Zone: Act 3 uses Labyrinth Zone's prototype decorative elements.
  • Final Zone: 3 rings are provided at the start of the zone, and the end of the zone is now a cutscene instead of being user-controlled.
  • New cutscene: After Final Zone's score tally, Tails (or Sonic if playing as Tails) will fly the Tornado onscreen, and the player character will hop on. The Tornado then flies through Emerald Hill Zone's background, before the Death Egg is shown rising out of a mountain in the distance. The Tornado finally lands at the start of Emerald Hill Zone.
  • Emerald Hill Zone: Contains prototype layout elements, and the scrapped Snail Badniks are replaced with the coconuts badniks.
  • Winter Zone: The Name of this Zone Here is called "Winter Hill" The graphics that are used are so similar (if not, almost identical) to Brenda Ross Mockup, with the layouts derived from the Sonic: Triple Trouble Robotik Winter. There are trees present but not Christmas trees. The BGM is a 16-bit recreation of Robotnik Winter Zone's music, and an original boss fight has been coded for it, named the "Penguin Blaster".
  • Wood Zone: The graphics are similar to what is seen in the Simon Wai prototype. It uses the Simon Wai prototype version of the Emerald Hill 2 player music as its BGM. It also has an original boss fight, named the "Saw Mobile".
  • Chemical Plant Zone: Small minor alterations were made, such as the loops having slanted corners from the Nick Arcade prototype.
  • Aquatic Ruin Zone: Uses music from the Simon Wai Prototype.
  • Casino Night Zone: Uses the background from the final, and foreground graphics & layout from the Final Release. The slot machines use graphics from the Sonic 3 slot machine bonus stage for consistency.
  • Mystic Cave Zone: Uses the Simon Wai prototype version of its music (essentially just slowed down).
  • Hidden Palace Zone (Sonic 2): The graphics are the same as those found in the Nick Arcade prototype and some from 2013 Mobile Version, with a layout extending from said prototype. A lift can be found on the long ramp; this was unused in the Nick Arcade prototype. This zone's boss is a near-perfect recreation of the Hidden Palace Zone boss from the 2013 Sonic 2 Mobile Version.
  • Sand Shower Zone: Uses graphics similar to the mockup screenshot. It's a desert-only setting. The zone has a custom boss fight against the Bead Worm, based on the boss of the same name from Sonic Chaos. The boss is set on a moving train in an homage to Mirage Saloon Zone.
  • Oil Ocean Zone: Takes its layout from the Knuckles in Sonic 2 with some extra objects.
  • Metropolis Zone: Uses the background from the Simon Wai prototype, and its layout appears to be a modification of the Simon Wai prototype that implements some of the final version's changes.
  • Cyber City Zone: The background uses all-new graphics, inspired by The Machine from Sonic Spinball. The foreground is a modified version of the foreground from Chemical Plant Zone. There is one act only, and the boss is a reimagining of Sonic Mania's Studiopolis Zone boss.
  • Sky Chase Zone: Uses the music from the Simon Wai prototype.
  • Death Egg Zone (Sonic 2): 3 rings are present at the start of the zone.
  • Launch Base Zone: Sonic and Tails fight the Big Arm at the end of the zone, like in Sonic 3 alone. And when defeated, The unused Eggman sprites are used here, after this a cutscene (S3&K Title Screen) is used for the transition from Launch Base to Mushroom Hill, this does not happen if playing as Knuckles.
  • Death Egg Zone (Sonic & Knuckles): At the start of the Kyodai Eggman Robo boss fight, 3 rings are provided.
  • Doomsday Zone: an infinity symbol (∞) is added to Ring Hud.

Game-Wide Content

In addition to all the zone changes above, Sonic Delta also has some changes that apply to the whole game.

  • Bonus stages: bonus stages are now accessed based on the remainder when you divide your ring count by 4: if the remainder is 0, you go to the slot machine; if it's 1, you go to Glowing Spheres; if it's 2, you go to the gumball machine; and if it's 3, you go to a Sonic 1 special stage with a 1-Up at the end instead of an emerald.
  • Special stages: the Sonic 1 and 2 zones now have Giant Rings hidden throughout the stage, like the S3&K zones. These rings send you to the half pipe stages from Sonic 2. Non-boss acts (excepting Scrap Brain act 2) have at least one giant ring hidden.
  • Knuckles & Tails: the entire game is playable as Knuckles with Tails following.
  • Knuckles story: starting a game as Knuckles or Knuckles + Tails plays his S3&K intro cutscene in Green Hill Zone. All bosses are piloted by the Eggrobo instead of Dr. Robotnik, including Flying Battery Zone. When flying onto Angel Island after defeating the Death Egg Robot, Knuckles is stopped by Mecha Sonic, much like he stops Sonic, which results in all the Chaos Emeralds being lost once again.
  • Hyper Tails: Tails can achieve a Super Form with just the Chaos Emeralds, which has no Super Flickies. His Super Emerald form is renamed to Hyper Tails, but otherwise remains functionally identical.
  • Act transitions: Sonic 1 and 2 now have seamless act transitions like S3&K does. Depending on how the acts are laid out, this may involve a wall to hide a background position shift, a short section before the official level starts to get Sonic to a different starting position, or simply placing the two acts next to each other.
  • Zone transitions: most Sonic 1 and 2 zones have transition cutscenes like S3&K does. These range from simply using a Dash Panel to run off screen, to (at the end of Sand Shower Zone) entering the engine cabin of a train and riding it into Oil Ocean Zone.

Options Menu

Version 0.68 introduced an options menu, which initially simply let you switch different music options in the game. It has since expanded to include several gameplay options as well.

  • Zone music options: Casino Night, Death Egg (Sonic 2), Hidden Palace, Metropolis, Oil Ocean, Sand Shower, Sky Fortress, Carnival Night, Ice Cap, and Launch Base zones all can toggle between their final and prototype versions (Simon Wai prototype for the Sonic 2 zones, Nov 3 1993 prototype for the Sonic 3 zones. Sand Shower "Prototype" music is Oil Ocean's final music, whereas Sand Shower's "Final" music is a remix of Yellow Desert Zone from Sonic Blast)

  • Boss music options: a wide variety of music can be selected for the Sonic 1 and 2 boss themes, the Sonic 3 miniboss theme can be swapped with its prototype/S&K version, and Knuckles's theme can be selected from the prototype, Sonic 3, or Sonic & Knuckles versions.

  • Misc music options: extra lives in Sonic 1 and 2 can be toggled between the S1/2 and S3&K jingles, and invincibility and Super Sonic songs in Sonic 1 & 2 can be set to a variety of options. Extra lives in S3&K can be toggled between the Sonic 3 and S&K versions, as can invincibility and Super Sonic songs (adding in the prototype Super Sonic music). Finally, the data select can be set to Sonic 2's level select music or Sonic 3's data select song, continue jingles and game over jingles can be toggled between S1/2 and S3&K, the score tally can be set to always use the Sonic 1 & 2 version or switch to the S3&K version in those levels, and the competition menu can toggle between its prototype and final songs.

  • Level title options: Spring Yard/Sparkling, Scrap Brain/Clock Work, Emerald Hill/Green Hill, Wing Fortress/Sky Fortress, Mystic Cave/Dust Hill, Cyber City/Genocide City, Aquatic Ruin/Neo Green Hill, and Mushroom Hill/Mushroom Valley zones can all be individually toggled between their final and prototype names.

  • Gameplay options: The maze and slot machine bonus stages can be set to have the original rotation from the official games, or smoother custom rotation. The half pipe and blue sphere special stages can be set to easier difficulties (half pipes requiring less rings to be collected, and blue sphere stages not speeding up). The Angel Island cutscene can be set to always use the prototype surfboard scene, or to only choose the surfboard scene if you don't have all Chaos Emeralds at that point, and the title screen can be toggled between the Sonic Delta screen and the Sonic 3 title screen. You can turn on Tails Assist (which is controlled with the B button), and switch monitor behavior between Sonic 1/2 and S3&K (S3&K allows you to break monitors from beneath them, whereas Sonic 1/2 makes monitors fall down if you hit them from below).

Additionally, the options menu includes special credits for everyone who contributed to the hack; access to the "Get Blue Spheres!" minigame that's seen when locking on Sonic 1 to Sonic & Knuckles; and a sound test that includes music arranged from several Master System and Game Gear Sonic games, the Sonic 3D Blast boss music, and the Virtua Racing menu (the lattermost of which is also the music that plays upon opening the options menu). This sound test is where you can enter in Cheat Codes (Level Select is 1-9-9-1-0-6-2-3, Debug Mode is 1-9-9-2-1-1-2-4, All Chaos Emeralds is 1-9-9-4-0-2-0-2 or 4-1-2-6, All Super Emeralds is 1-9-9-4-1-0-1-8, and Bridge Zone is 1-9-7-7-0-9-0-5). Once you enter the Bridge Zone cheat code, its music will play and the Play "Bridge" option will appear below the sound test, allowing you to play both acts of Bridge Zone.


Latest version

Please go to the official website for latest version. You can also visit the Neto-Games Discord for Beta Updates, and helping him finding bugs.

Prior versions

  • Versions in between 0.39a and 0.59, 0.61 to 0.64, 0.66 to 0.74, and after 0.75 are not uploaded at this time, please visit the link above to see if a new version is available!
Download.svg Download Sonic Delta
File: Sonic_Delta_v075.rar (2.89 MB) (info)
Current version: v0.75

See also

External links

Sonic Retro
Release thread
at Sonic Retro.