Difference between revisions of "Sonic the Hedgehog (16-bit)"

From Sonic Retro

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* ''[[Sonic the Hedgehog (Android)]]'' for Android mobile phone handsets (2011)
* ''[[Sonic the Hedgehog (Android)]]'' for Android mobile phone handsets (2011)
* ''[[sega:Sega Mega Drive Classic Collection Gold Edition|Sega Mega Drive Classic Collection Gold Edition]]'' (2011)
* ''[[sega:Sega Mega Drive Classic Collection Gold Edition|Sega Mega Drive Classic Collection Gold Edition]]'' (2011)
* ''[[Sonic the Hedgehog (Playstation Network)]]'' on Playstation Network (2011)

Revision as of 10:27, 27 August 2011

"Sonic 1" redirects here. For the Master System/Game Gear version, see Sonic the Hedgehog (8-bit). For other games with the same title, see Sonic the Hedgehog (disambiguation).


Sonic1 title.png
Sonic the Hedgehog
Publisher: Sega
System(s): Sega Mega Drive/Genesis
ROM size: 512 Kilobytes
Genre: 2D Platform

Sonic the Hedgehog (ソニック・ザ・ヘッジホッグ) is the first game in the long-running series by video game publisher and former console maker Sega. First released in the United States and Europe on June 23rd, 1991, it was the premier outing for the character of Sonic the Hedgehog and the group behind his creation, Sonic Team. Though the game only received marginal success in its home country, almost overnight Sonic became a sensation in the West, solidifying Sega's place in Europe and turning the company into a household name in the United States.

For the first time, a company was able to directly compete with console and gamemaker Nintendo, which had dominated the second half of the 1980's. Though Nintendo still reigned supreme in Japan, the highly-contested 16-bit war in the West was a marvel to behold, the big two being neck and neck through almost the entirety of the third generation of console gaming.

The game propelled the creators into the realm of video game superstardom, programmer Yuji Naka for a time becoming the face of Sega much as Shigeru Miyamoto became the face of Nintendo after the success of Super Mario Bros. The franchise took off, with a version of the game being released on the Sega Master System and a series of sequels across Sega's various consoles over the years. It not only became the definitive title for the system and replaced Altered Beast as the pack-in title for the West, but would go on to be ported to no less than twenty platforms since its initial release.


File:Sonic1 jp manual 08 09.gif
The story to Sonic the Hedgehog.

Somewhere in the ocean lies an island not found on any map, known by its inhabitants as South Island. The reason for it being absent is a simple, yet mysterious one: it does not have a fixed position, instead traveling through the seas on its own course. While the reason for this behavior is unknown, it is rumored that it may have something to do with the legendary gemstones known as the Chaos Emeralds. Though legend says they exist on the island, no one knows exactly where they are or how to get a hold of them. All they do know is of the incredible power they are said to contain, and how they can give energy to all living beings.

Learning of the existence of the Chaos Emeralds, the mad genius Dr. Eggman sets himself on a quest to locate the emeralds for his own use, wanting to harness their power for his many mechanical creations. With the plan in motion, Eggman creates his base in a corner of the island, which he dubs the Scrap Brain Zone. However, he is aware that his evil plans will more than likely be interfered by Sonic the Hedgehog.

Though not a native of the island, Sonic the Hedgehog would often find himself on its mystical shores, and more than once had he run into the evil doctor, foiling an untold number of schemes. Just as Eggman predicted, in no time at all does the blue hedgehog learn of the doctor's intentions, running at sonic speed to confront him.

It doesn't take long for Sonic to realize that something is amiss, and is shocked to learn that Eggman has gone a step further with his evil intentions. Kidnapping the many animals living on the island, he has methodically been placing them in robot shells and using them to scour the island in search of the emeralds. Realizing that Eggman has turned Sonic's friends into his own personal mechanical army, Sonic wastes no time. Running across the island, he must not only stop Eggman's latest scheme and gather the Chaos Emeralds, but free his friends in the process.

"Hurry! Sonic the Hedgehog - everyone is waiting for your help!"

Game Mechanics


Sonic the Hedgehog facing off against his arch-rival, Dr. Eggman.

At its heart, Sonic the Hedgehog is a platformer. Taken from the same mold as platformers previous, Sonic Team was able to make the experience unique enough to rise it above the numerous Mario clones that had flooded the market. Becoming the standard for the Mega Drive, the game was also developed to showcase the potential of the system, creating a smooth-running and fast-moving game that is simple to pick up but complex and engaging underneath.

Broken up into six "Zones" with three "Acts" each (plus a "Final Zone" at the end, a single Act consisting of a final boss confrontation), the game operates under a very basic platforming premise: to traverse across each of these Acts under a certain amount of time (in this case ten minutes) and overcome whatever enemies and obstacles may be in your way. The flow of each of these Zones presents an interesting duality in terms of playthrough. While it is possible to go through each act slow and methodically, it is just as simple to run through the Zone as fast as possible, playing for the shortest time as opposed to the highest score. Featuring multiple pathways and plenty of secret areas, the eighteen main courses were created specifically with replayability in mind, with game director Hirokazu Yasuhara wanting a game that could stand the test of time, something more than a basic arcade experience.

Thanks to the efforts of Yuji Naka, the engine by which Sonic the Hedgehog is powered focuses not only on the potential speed for the character, but establishes the physics for the world as well. Being one part "pinball" and one part "momentum", the movement of Sonic depends just as much on the unique terrain of each level as it does on the input of the player. When it comes to the now-iconic set pieces of loop-de-loops and curved slopes, Sonic can only run through them if he has built up enough momentum to traverse through it. Running on curved slopes, a player can press downward on the control pad, allowing Sonic to curl up into a ball and gain tremendous speed - the steeper the slope, the higher the max speed at the end. Even the angles for which Sonic bounces off bumpers and springs are determined by the values within, making the Sonic experience unique from what other games were presenting at the time.

Sonic the Hedgehog rolling downward in Spring Yard Zone.

In terms of the moveset, the original Sonic the Hedgehog chooses to keep it simple. A secondary button is not needed to increase Sonic's speed, only time. Each of the three buttons on the Mega Drive controller were mapped to the same action, giving the player the power to make Sonic jump up, curling into a ball in the process. With this spin attack, Sonic can break an enemy from any angle, provided a spiked surface or a fire projectile is not in the way. He can also curl into this ball from on the ground, but can only remain as long as there is some momentum behind it. Once Sonic slows down, he is forced to return to his standing (or crouching) pose.

Scattered throughout each level are also a variety of items, the most famous of these being the spinning golden rings. While collecting 100 of these will award Sonic with an extra life, they serve a much more important function: as long as Sonic has at least one in his possession, he can not be killed by an enemy or spikes, though he can still succumb to crushing or drowning. Being hit while having rings causes them to scatter, making Sonic temporarily invincible to give the player time to recover and try to collect the scattered rings before they disappear.

Another prominent item featured in each Zone are the variety of item boxes. Resembling computer monitors, each give Sonic a different reward depending on the image inside. If a ring is pictured, for instance, the player gets an extra 10 rings added to their ring count. If the icon is a group of stars, Sonic is awarded with temporary invincibility. A shoe icon allows the character to (temporarily) run even faster than what can normally be achieved, and a shield icon gives Sonic a barrier that will protect him from a hit, either maintaining his ring count or not killing the player if no rings are available. Another common item found on the playfield are Lamp Posts, allowing Sonic to start at that point in the level in the case of the player losing a life, as opposed to starting the act from the beginning again. These, along with other level features such as springs, spikes, and bumpers, create a landscape that would be featured again and again within the Sonic the Hedgehog series.

Dr. Eggman taunting the player when you complete the game without all six Chaos Emeralds.

At the end of the first two Acts in each Zone, a Signpost with Eggman's face is there to greet you, as you run by it and turn it to Sonic's profile signaling your victory. However, at the end of each third Act, the player is greeted with an appearance from the main antagonist in his Eggmobile hovercraft, modified to present the player with a new challenge, with each Zone. Needing eight hits to be defeated, the doctor scurries away, allowing Sonic to open the animal capsule and free his friends, signaling the end of that particular Zone.

There is another element to the gameplay, a sort of "side mission". At the end of the first two Acts of each Zone, if the player has at 50 rings when reaching the Signpost, a Giant Ring appears to the right of the post, floating silently just as the standard rings do. If Sonic jumps into the ring in time, he will be transported to the Special Stage, a maze rotating 360 degrees. If traversed correctly, the player will be rewarded with a Chaos Emerald. Though not essential in a basic runthrough, collecting all six emeralds is the only way to witness the true ending to the game. If not done, Eggman will taunt you at the end, asking you to "try again".

Graphical Style

The graphical style of Sonic the Hedgehog was extremely impressive for its time, especially for the Mega Drive hardware (the Super Nintendo being technically superior in terms of graphic capabilities). With a color pallette expanded beyond what 8-bit systems could do, each zone was given a unique and rich look. The graphical style was inspired by the then-new world of "computer generated" graphics, the visuals of the Green Hill Zone being the most prime example. Even the sprites of Sonic, Eggman, the enemies, and the rings reflected on this, each richly animated object jumping out of the screen. While other games of the era can look dated, Sonic the Hedgehog has been able to maintain a timeless feel, emphasized by the visual work of Naoto Ohshima and the fact that the original game still sells, albeit on modern hardware.

Music and Sound

Utilizing the onboard Zilog Z80 microprocessor and Yamaha YM2612 synthesizer sound chip, Sonic the Hedgehog was able to create a sound that was also unique, with the jumps, springs, and ring collecting sounds being an intergral part of the Sonic experience. The sounds created by the sound team would be reused in subsequent entries, the classic ring sound still being heard with each new Sonic game. The music to the game, composed by DREAMS COME TRUE artist Masato Nakamura, also became a highly praised game soundtrack. The first two songs written, the Green Hill Zone theme and the title screen jingle, would be alluded to in subsequent games, becoming the quintessential score of Sonic the Hedgehog. The popularity of the soundtrack has also made it a standard in live videogame music performance tours such as Video Games Live and Play! A Video Game Symphony.


The following is an explanation on how the scoring process works within the game:

Hitting bumpers (Spring Yard Zone etc): 10 points for each of the first ten hits on any given bumper; after that no more points can be gained from that bumper

Hitting enemies (a "chain" refers to all enemies destroyed until the next time Sonic lands on some form of ground):

  • First enemy in a chain = 100
  • Second enemy in a chain = 200
  • Third enemy in a chain = 500
  • Fourth through fifteenth enemies in a chain = 1000 each
  • Sixteenth and all subsequent enemies in a chain = 10000 each

Destroying a Dr. Eggman boss robot: 1000 points

Ring bonus at end of level: 100 points for each ring held

Time bonus at end of level:

  • Game clock reads 0:29 or less = 50000
  • Game clock reads 0:30 to 0:44 = 10000
  • Game clock reads 0:45 to 0:59 = 5000
  • Game clock reads 1:00 to 1:29 = 4000
  • Game clock reads 1:30 to 1:59 = 3000
  • Game clock reads 2:00 to 2:59 = 2000
  • Game clock reads 3:00 to 3:59 = 1000
  • Game clock reads 4:00 to 4:59 = 500
  • Game clock reads 5:00 or more = 0

End-of-level flags: Where the Signpost stands, there are sometimes flags you can trigger. These flags are hidden, but if you hit them they will appear and show either 100, 1000, or 10000. The flags that say "100" are really only worth 10 points each, but the 1000 and 10000 flags report their values accurately.

Special Stage: 100 points for each ring held

Sound Test

The level select to Sonic the Hedgehog, also containing the sound test.

Below is a listing of the songs available to played through the sound test within the game, accessible through the level select code. For the songs themselves, visit the Sonic the Hedgehog OSV.

Production Credits

Director ("Game Plan"): Hirokazu Yasuhara (as "CAROL YAS")
Programmer: Yuji Naka (as "YU2")
Character Artist ("Character Design"): Naoto Oshima (as "BIGISLAND")
Zone Artists ("Design"): Jina Ishiwatari (as "JINYA"), Rieko Kodama (as "PHENIX RIE")
Composer ("Sound Produce"): Masato Nakamura
Sound Programmers ("Sound Program"): Hiroshi Kubota (as "JIMITA") [Sound Programming], Yukifumi Makino (as "MACKY") [Sound Effects and Jingles]
Special Thanks: Fujio Minegishi, "PAPA"



Logo Design

The distinctive "ribbon, ring, and stars"-styled title screen used in the first Sonic the Hedgehog and subsequent installments was something of a theme in early Sega games. The Sonic version is based on the title screen from the 1988 Sega arcade game Wonder-Boy III: Monster Lair, which bears similarities to that of the 1986 Sega arcade game Alex Kidd: The Lost Stars.

File:AlexKiddLostStars.png File:Wb3 title.png Sonic1 title.png

Game Revisions

The original release of the game lacked parallax scrolling, moving clouds (Green Hill Zone), rippling water (Labyrinth Zone), a correct Level Select screen arrangement, and other minor details. These effects were added in the later Japanese and Korean release, known as REV01. The much later "JP2" version found in Sonic Mega Collection was an officially hacked ROM which "fixed" the "Spike Bug".

Hivebrain has documented the changes between the first version and the newer Japanese/Korean version, which is provided below:

  1. "clr.l" used instead of "move.l #0" in ClearScreen.
  2. Garbage removed from CalcSine.
  3. "TM" on Sega screen is hidden if the console is Japanese.
  4. "TM" on title screen isn't loaded if the console is Japanese.
  5. AddPoints gives you an extra life for every 50000 points.
  6. Level select stage order is correct.
  7. Level select code is UDDDLR (instead of UDLR) if the console is Japanese.
  8. Moved restart level flag check in Level_MainLoop.
  9. Added background scroll check to LZWaterFeatures.
  10. d2 is cleared in a slightly different way in MoveSonicInDemo.
  11. Added gamemode check in SS_MainLoop.
  12. Tidied EndSTH (obj89).
  13. Layer scrolling changed.
  14. Tile drawing changed.
  15. Stuff added to DLE_MZ1.
  16. Blank frame added to rings mappings [1].
  17. Added check in monitor contents item to prevent interruption of drowning music [2].
  18. Lamppost time is cleared after game over (obj39).
  19. Tidied MarbleBrick (obj46).
  20. Tidied FloatingBlock (obj56).
  21. Minor change to DrownCount (obj0A).
  22. Changes to Caterkiller (obj78).
  23. Minor change to Labyrinth boss (obj77).
  24. Minor changes to Final boss (obj85), including 1000 point bonus for killing it.
  25. Ending sequence debug list changed.
  26. Some unneeded things removed from Pattern Load Cues.
  27. Sega logo graphics and mappings slightly different.
  28. Unused graphics data removed.
  29. MZ & SBZ 256x256 tiles modified.
  30. SS5 & SS6 layouts modified.
  31. SYZ background modified.
  32. Minor change to SolidObject subroutine [3].

GoodGen Version Index

  • Sonic the Hedgehog (W) (REV 00) [!] - The standard first release of Sonic 1.
  • Sonic the Hedgehog (W) (REV 01) [!] - Japan/Korea-only version of Sonic 1, with graphical enhancements.
  • Sonic the Hedgehog (W) (REV XB) - Release with graphical enhancements and with the spike-bug fixed.
  • Sonic the Hedgehog (W) [p1][!] - Pirate version of Sonic 1, with copyrights, logos and serial number removed.
  • Sonic the Hedgehog (W) [p2][!] - Pirate version of Sonic 1, with copyrights and logos removed.



{{{{{icon}}}|L}} Expression error: Unexpected < operator. Sonic Retro Average
Based on 5 reviews
Publication Score Source
Electronic Gaming Monthly 90
GamePro 96
Computer and Video Games 94
Mean Machines Sega 92
Raze 95

ROM Modification


Disassemblies are like source codes. You can modify them how you want, reassemble them, and play it. Even though the ROM will be shifted, it will work because of labels.

Hacking Guides

Image Galleries

Physical Scans

Mega Drive, JP
Sonic1 box jap.jpg
Mega Drive, US
Sth md us cover.jpg
Mega Drive, US (Not for resale)
Sonic1 box us nfr1.jpg
Mega Drive, US (Classic)
Sonic1 md us classic cover.jpg
Mega Drive, EU
Sonic1 box eu.jpg
Mega Drive, BR
Sonic1 MD BR Cart.jpg
Mega Drive, CA
Sonic1 MD CA Box.jpg
Mega Drive, KR (Second print)
Sonic1 MD KR Box 2.jpg


See Also

  • Sonic the Hedgehog Story Comic - A three volume comic released in Japan used to advertise the game. Contained in the narrative are elements there were eventually changed or removed from the final product.
  • Sonic the Hedgehog (promotional comic) - A standalone story commissioned by Sega of America using the westernized story no longer considered canon.

External Links

Sonic the Hedgehog (16-bit)
Sonic1 title.png

Main page (Gen|2013|3D|Ages)

Print advertisements
TV advertisements
Magazine articles

Hidden content (Gen) (2013)
Bugs (Gen)
Region coding
Hacking guide



Sonic games for the following systems
 2010  Sonic the Hedgehog | Sonic Spinball | Dr. Robotnik's Mean Bean Machine | Sonic 3D: Flickies' Island | Sonic & Sega All-Stars Racing     2011  Sonic the Hedgehog 2 | Sonic the Hedgehog 3 & Knuckles | Sonic Adventure | Sonic Generations     2012  Sonic the Hedgehog 4 Episode I | Sonic the Hedgehog CD | Sonic the Hedgehog 4 Episode II | Sonic Adventure 2     2013  Sonic & All-Stars Racing Transformed     2015  Sonic Lost World     2017  Sonic Mania | Sonic Forces     2019  Team Sonic Racing    
Wii Virtual Console
 2006  Sonic the Hedgehog | Dr. Robotnik's Mean Bean Machine     2007  Sonic the Hedgehog 2 | Sonic the Hedgehog 3 | Sonic Spinball | Sonic 3D: Flickies' Island     2008  Sonic the Hedgehog (8-bit) | Sonic the Hedgehog 2 (8-bit)     2009  Sonic Chaos | Sonic & Knuckles     2010  Sonic the Hedgehog 4 Episode I    
Sega Mega Drive

Sega Mega-CD
Sega 32X
 1991  Sonic the Hedgehog | Sonic Eraser     1992  Sonic the Hedgehog 2     1993  Sonic the Hedgehog CD | Dr. Robotnik's Mean Bean Machine | Sonic Spinball     1994  Sonic the Hedgehog 3 | Sonic & Knuckles     1995  Chaotix | Sonic Classics     1996  Sonic 3D: Flickies' Island