SegaSonic the Hedgehog was Sonic the Hedgehog, Mighty the Armadillo, and Ray the Flying Squirrel's only game together until the release of Sonic Mania Plus in 2018.
- There are loads more sprites that could be included here, including Robotnik's many, many other sprites (Source). Check for other things, like unused sounds or debug menus to uncover.
- This guy on Twitter has found a plethora of unused content (there may be more tweets): , , , . He has since documented all his findings on his website. Put all of that content on this page (with proper credit of course).
Early versions of the characters on the title screen, without the shine on the eyes and the nose missing/unfinished. Sonic's quills are also shaped a little different in this early version. While Sonic was seen in the prototype, Ray and Mighty were nowhere to be seen outside of the graphics data.
Player Character Graphics
Some sprites of the characters flexing their muscles, which possibly would have been used when continuing the game. The code to have these animations display in-game still exists, but doesn't appear to be used anywhere.
Sonic had his face mercifully redrawn to look less like roadkill, while Ray got his patagia enlarged.
Sonic got his arms reanimated, Ray had his proportions slightly corrected, and Mighty's mouth was slightly redrawn, and his eyes are now closed.
Dr. Eggman Sprites
It seems that Eggman was supposed to use some gadgets and thingamajigs himself to prevent players from reaching him. Probably meant to show up in other stages in Eggman Island more than waiting for the main character(s) to meet him at the computer room in the final level.
Unused Localization Version
Although the international releases were, for whatever reason, not localized or translated, there are many remnants of plans to do so.
A largely complete set of sprites of Robotnik as he looked on ABC's Sonic the Hedgehog cartoon (generally nicknamed SatAM) and in Archie's Sonic comics. The only sprites that appear to be missing are for him riding around behind the title screen and the intro where he traps the main character(s) while riding on an Eggman-face tank.
Even the little details were accounted for to complete the Robotnik experience.
A complete set of English dialogue bubbles. Interestingly, one of the bubbles has an "Eggman" variant.
Unused Text Strings
Attract Mode Order
Demo 1 Mode
Demo 2 Mode
This is located at 0x463 in Rev. A and 0x60D in the final. The entries here correspond to the attract mode within the game.
Removed Debug Tools
Fence Set Mode
Stg St Wait
Starting at 0x19F9 in Rev. A and 0x254D includes a block of strings which contain remnants of debugging tools. "RING BINUS" might've appeared below the player health icons to label the ring counter, but was probably removed due to it being a waste of space.
This string only appears in the final build, at 0x27E2. This appears before code related to the character select screen, which would've made it placeholder text.
These strings also only appear in the final build, specifically at 0x11413E. This was placeholder text below the player icons.
These might have been used when setting to multiple coins per one credit, but they don't appear no matter what dipswitch settings are used.
A sprite viewer menu of sorts.
|Sega Genesis||Sonic the Hedgehog (Prototype) • Sonic the Hedgehog 2 (Prototypes) • Sonic the Hedgehog 3 (Prototype) • Sonic & Knuckles (Prototypes) • Sonic 3 & Knuckles • Sonic 3D Blast (Prototypes)|
|Sega Master System||Sonic the Hedgehog • Sonic the Hedgehog 2 • Sonic Chaos (Prototypes) • Sonic Blast|
|Game Gear||Sonic the Hedgehog (Prototype) • Sonic the Hedgehog 2 (Prototype) • Sonic Chaos (Prototypes) • Sonic Triple Trouble (Prototypes) • Sonic Labyrinth • Sonic Blast (Prototypes)|
|Arcade||SegaSonic the Hedgehog (Prototype)|
|Sega CD||Sonic the Hedgehog CD (Prototypes)|
|32X||Knuckles' Chaotix (Prototypes)|
|Windows||Sonic the Hedgehog CD (1996, 2011) • Sonic 3D Blast|
Sonic Heroes • Sonic Adventure DX: Director's Cut (2004, Demo, 2011) • Sonic Adventure 2 • Sonic the Hedgehog 4: Episode I (Prototypes) • Sonic the Hedgehog 4: Episode II (Prototype)
Sonic Generations (Demos) • Sonic Lost World • Sonic Mania • Sonic Forces • Sonic Colors: Ultimate
|Sega Saturn||Sonic X-treme • Sonic 3D Blast (Prototype)|
|Dreamcast||Sonic Adventure (Prototypes) • Sonic Adventure 2 (Prototypes)|
|Neo Geo Pocket Color||Sonic the Hedgehog Pocket Adventure (Prototypes)|
|Game Boy Advance||Sonic Advance (Prototype) • Sonic Advance 2 • Sonic Advance 3 (Prototype) • Sonic the Hedgehog Genesis|
|GameCube||Sonic Adventure 2: Battle (Demo) • Sonic Adventure DX: Director's Cut (Prototypes) • Sonic Heroes (Prototypes) • Shadow the Hedgehog|
|PlayStation 2||Sonic Heroes • Shadow the Hedgehog • Sonic Unleashed|
|Xbox||Sonic Heroes • Shadow the Hedgehog|
|Nintendo DS||Sonic Rush (Demo)|
|Xbox 360||Sonic the Hedgehog (Demo) • Sonic Unleashed (Preview) • Sonic the Hedgehog 4: Episode I (Prototypes) • Sonic Generations (Demos) • Sonic Adventure 2|
|Wii||Sonic Unleashed • Sonic Colors • Sonic the Hedgehog 4: Episode I (Prototypes) • Sonic and the Black Knight|
|PlayStation 3||Sonic the Hedgehog • Sonic Unleashed • Sonic the Hedgehog 4: Episode I (Prototypes) • Sonic Adventure 2 • Sonic Generations (Demos)|
|Nintendo 3DS||Sonic Generations|
|Wii U||Sonic Lost World • Sonic Boom: Rise of Lyric|
|PlayStation 4, Xbox One, Nintendo Switch||Sonic Mania • Sonic Colors: Ultimate|
|J2ME||Sonic the Hedgehog Mobile|
|iOS, Android||Sonic the Hedgehog 4: Episode I (Prototypes) • Sonic the Hedgehog • Sonic the Hedgehog 2 • Sonic the Hedgehog CD|
|Game Gear||Sonic Drift 2|
|Windows||Sonic R • Sonic Riders • Sonic & SEGA All-Stars Racing • Sonic & All-Stars Racing Transformed • Team Sonic Racing|
|Sega Saturn||Sonic R (Preview)|
|PlayStation 2||Sonic Riders • Sonic Riders: Zero Gravity|
|PlayStation 3, Wii U||Sonic & All-Stars Racing Transformed|
|GameCube, Xbox||Sonic Riders|
|Nintendo DS||Sonic & SEGA All-Stars Racing|
|PlayStation Portable||Sonic Rivals|
|Xbox 360||Sonic & SEGA All-Stars Racing • Sonic & All-Stars Racing Transformed|
|Wii||Sonic & SEGA All-Stars Racing • Sonic Riders: Zero Gravity|
|Nintendo 3DS||Sonic & All-Stars Racing Transformed|
|Sega Genesis||Sonic the Hedgehog Spinball (Prototype)|
|Sega Master System||Sonic Spinball|
|Game Gear||Sonic Spinball (Prototype)|
|Game Boy Advance||Sonic Battle|
|Nintendo DS||Mario & Sonic at the Olympic Games (Beijing 2008)|
|Wii||Mario & Sonic at the Olympic Games (Beijing 2008, Vancouver 2010, London 2012)|
|Nintendo 3DS||Mario & Sonic at the Olympic Games (London 2012)|
|Wii U||Mario & Sonic at the Olympic Games (Rio 2016)|
|J2ME||Sonic at the Olympic Games|
|Sega Genesis||Dr. Robotnik's Mean Bean Machine (Prototype)|
|Sega Master System, Game Gear||Dr. Robotnik's Mean Bean Machine|
|Sega Master System||Sonic's Edusoft|
|Sega Pico||Sonic the Hedgehog's Gameworld • Tails and the Music Maker (Prototypes)|
|LeapFrog Systems||Sonic X • Sonic the Hedgehog|
|Sega Genesis||Sonic Classics|
|Sega Saturn||Sonic Jam (Prototype)|
|Windows||Sonic & Knuckles Collection|
|GameCube||Sonic Mega Collection (Prototype) • Sonic Gems Collection|
|PlayStation 2||Sonic Gems Collection|
|Nintendo DS||Sonic Classic Collection|
|Plug & Play||Super Sonic Gold|
|Game Gear||Tails' Skypatrol • Tails Adventures|
|Arcade||SegaSonic Cosmo Fighter|
|Dreamcast||Sonic Shuffle (Debug Version)|
|Nintendo DS||Sonic Chronicles: The Dark Brotherhood|
|iOS, Android||Sonic Jump • Sonic Dash • Sonic Runners • Sonic Runners Adventure (Prototype)|
|Adobe Flash||Sonic and the Black Knight: Knight in Training|