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Sonic the Hedgehog 3

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This page contains changes which are not marked for translation.

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English • ‎한국어

Title Screen

Sonic the Hedgehog 3

Also known as: Baramdori Sonic 3 (KR)
Developers: Sonic Team, Sega Technical Institute
Publishers: Sega (JP/US/EU), Samsung (KR), Tec Toy (BR)
Platform: Genesis
Released in JP: May 27, 1994
Released in US: February 2, 1994
Released in EU: February 24, 1994
Released in KR: 1994
Released in BR: 1994

AreasIcon.png This game has unused areas.
CharacterIcon.png This game has unused playable characters.
CodeIcon.png This game has unused code.
EnemyIcon.png This game has unused enemies.
GraphicsIcon.png This game has unused graphics.
MusicIcon.png This game has unused music.
SoundIcon.png This game has unused sounds.
DebugIcon.png This game has debugging material.
SoundtestIcon.png This game has a hidden sound test.
LevelSelectIcon.png This game has a hidden level select.
RegionIcon.png This game has regional differences.

BugsIcon.png This game has a bugs page

Sonic the Hedgehog 3 is the third game in the 16-bit Sonic trilogy and the first game with the redheaded echidna, Knuckles. Originally one big game, Sonic 3 was split into two games due to time constraints and cartridge costs; the second half of the story is its direct sequel, Sonic & Knuckles.

Level Select/Debug Mode

There's some heritage here... and Mushroom Hill is named Mushroom Valley.

To access a level select and debug mode, press Up, Up, Down, Down, Up, Up, Up, Up after the SEGA logo screen fades to black and Sonic begins to move, but before the title screen appears (about 4.31 seconds after boot). You only have about 1.3 seconds to enter it, and due to this screen having an absolutely ridiculous number of lag frames, it may not always work; you'll hear the ring collection sound if you did it right. Alternatively, you can activate the Sonic 2 menu (see below) and enter the Sonic 2 level select code (19, 65, 09, 17).

Level Select

To find the level select on the title screen, simply press Up to reveal "SOUND TEST" and press Start. To activate debug mode, select a file/level, hold A and press Start, and keep holding A until the level begins. You can also hold C and press Start to highlight high-priority background tiles (tiles that overlap Sonic and other sprites).

Debug Mode

While in debug mode, you have access to the following:

  • Invincibility
  • Infinite time
  • Debug coordinates (in place of score)
  • Sprite counter (in place of time)
  • Placement mode: Press B to enter placement mode, which allows you to move Sonic anywhere in the level with the D-Pad and place objects from a predefined list (not all objects may be available in a given level). In this mode:
    • Press A to move forward one object.
    • Hold A and press C to move backward one object.
    • Press C to place the object.
    • Press B again to return to normal gameplay.
  • Character animation viewer: hold C and press B to rapidly cycle through all available animation frames for the current character (pause the game and use frame advance to view individual frames). Press B again to return to normal gameplay.
  • Pause options:
    • Press A to go back to the level select.
    • Hold B to progress the game in slow motion.
    • Press C to advance one frame.

If you die, press B to enter placement mode, and then press B at a safe spot to revive yourself. However, trying to place an object in this death state will freeze the game. Additionally, do not enter debug mode at any point where Sonic's sprite rotates (such as while standing on the red-and-white cylinders in Carnival Night Zone) or the game will crash.

Alternatively, use Game Genie code AA6T-AAXC to access the level select.

A third way to unlock the level select menu (if you don't mind risking the long-term health of your console and cartridges) is to load up Sonic 2, unlock its level select (19, 65, 09, 17 in the sound test), swap the cartridge with Sonic 3 without turning the power off, and then press Reset. This works because the RAM variable that unlocks the level select is preserved when you reset the console (Sonic 3 was built upon the Sonic 2 source code, and thus shares a number of RAM variables).


The level select menu shows what the level order was at one point. The Sonic 3 Zones are in their normal order, but Flying Battery from Sonic & Knuckles is listed between Carnival Night and Ice Cap. Following Launch Base are Mushroom Valley (an early name for Mushroom Hill) and Sandopolis, but neither of those can be selected.

According to commentary from the Sonic Jam strategy guide, Ice Cap was meant to follow Flying Battery as Sonic was supposed to break down the door at the end of the latter Zone and use it as a snowboard. There's also a variety of unused songs, all from Sonic & Knuckles, in the sound test.

Further, all the graphics here (including the level icons) are recycled from Sonic the Hedgehog 2, and the icons are shown in the Sonic 2 order, such as Emerald Hill's icon for Angel Island and Casino Night's icon for Carnival Night. Interestingly, the second "2P VS" entry shows the unused Hidden Palace icon from the Sonic 2 prototypes.

Red Revolving Spheres

I wonder if this is linked to the Red Ring of Death?

A spinning mass of red spheres, which can be placed in the first half of Angel Island Act 1 via debug mode. The spheres resemble those that appear in the game's special stages, but the object itself seems to have no apparent gameplay purpose. When it is placed, many palette and VRAM complications occur in the level, and the game slows down considerably. The object can be manipulated with the second controller.

  • Up - rotates the object vertically.
  • Right - rotates the object horizontally.
  • Down/Left - moves the object up or down.
  • A/C - changes the object's size.
  • B - rotates the object sideways.
  • Start - toggles automatic rotation.

Knuckles Leftovers

Some data for Knuckles as a playable character seems to still exist in the game. Game Genie codes ASCA-AAHC ASCA-BA9Y or Patch Code FFEF4C:0003 will allow you to "select" Knuckles as your character. You will play as Sonic, but have Knuckles' character select, continue icons, and "level-clearing" text. The end signpost will also feature Knuckles, though the image uses Sonic's blue palette, markers of the scores screen of Special Stages uses color palette to Knuckles. As you might expect, this code will save properly, allowing you to apply the code, create a save, then continue to use "Knuckles" even without the Game Genie.

So, does this mean we can play as Knuckles without Lock-On? Sonic?! What the devil are you doing here?!

Bugs and oddities

  • The cutscene where Sonic arrives on Angel Island is corrupt and Sonic can fall into the ground and lose a life.
  • The Insta-Shield graphics disappear at times.
  • At the start of Ice Cap Act 1 the cutscene is the same as Tails'.
  • The Pit in the beginning of Ice Cap Act 1 does not work correctly and will cause you to lose a life when entering the loop point.
  • In Launch Base Act 1, the cutscene where Knuckles throws a bomb works, but the building does not load.
  • In Launch Base Act 1 when you defeat the mid-boss, a game-ending bug appears that makes you stuck in the room.
  • There is no level select even if you have all the emeralds.

Eighth Special Stage

Sonic3 unused special stage in game.png
Feeling dizzy?

There is an eighth Special Stage with a gray Chaos Emerald (much like the seventh Emerald) that is inaccessible during normal gameplay. To access it, open the level select, set the sound test selection to 07, then hold A and press Start on "Special Stage 2".

The stage is fully playable, although it may occasionally slow to a crawl when collecting a blue sphere, which may have contributed to its removal. The Emerald has no special effect in-game, and does not appear on the end-of-stage tally in any form other than a score increase.

(Source: Sonic Retro)

Sonic & Knuckles Zones

To do:
  • Post a save-state here.
  • Is there any way to fully access the other zones?

A few remnants of the Sonic & Knuckles zones are still left in the game. As mentioned earlier, Flying Battery would have been played between Carnival Night and Ice Cap, but when the game was split into two that zone was moved into Sonic & Knuckles to give it more levels. Most of the data that once belonged to these levels either isn't present in the game anymore or isn't currently accessible. Still, there's some leftovers of Flying Battery in Sonic 3: a data select icon, its music, and even its bosses!

You can "access" these zones using the following Game Genie codes:

Zone Act 1 Code Act 2 Code
Flying Battery ABZA-AJE8 AFZA-AJFA
Sky Sanctuary ABZA-AYF0 AFZA-AYF2
Death Egg ABZA-A0F4 AFZA-A0F6
The Doomsday ABZA-A2GG AFZA-A2GG
Glowing Spheres Bonus Stage ABZA-BJF8 AFZA-BJGA
Slot Machine Bonus Stage ABZA-BLF8 AFZA-BLGA
Lava Reef Act 3/boss ABZA-BREW
Hidden Palace AFZA-BREY
Death Egg Final Boss AFZA-BRE0
Hidden Palace (Special Stage Ring) AFZA-BRE2

Each level can be played through the level select. Lava Reef, Sky Sanctuary and Death Egg are accessible using the first, second and third 2P VS options respectively while The Doomsday Zone uses the Sound Test option. The glowing spheres and the slot machine bonus stages can be played by selecting "Bonus" on the level select. "Ending" can be accessed by selecting Angel Island Zone Act 1 and 2. Lava Reef Act 3 and Hidden Palace can be played by selecting Hydrocity Zone. Finally, The Death Egg final boss and Hidden Palace (Special Stage Ring) can be accessed through Marble Garden Acts 1 and 2.

Notice that you need to access these zones in a specific way. Currently, using only these codes will crash the game for most of the stages but it'll still play the correct music. Flying Battery Zone can be fixed using codes W4ZT-LE0R + 3CZT-LJ8W for Act 1 and W4ZT-LE1G + 3CZT-LJ9L for Act 2. It will be corrupted with glitchy collision and Ice Cap tiles appearing all over the place. However, some graphic tiles will not be overwritten and will use whatever was last loaded there which can make this zone even glitchier. Other Sonic and Knuckles Zones' such as the Death Egg final boss, Hidden Palace, Lava Reef Act 3/boss, and Hidden Palace (Special Stage Ring) can accessed without the game crashing, although they are very glitched. The Bonus stages will work, but only on a real Sega genesis for some odd reason.

It is possible to use Sonic 3C's savestates to access the remaints of the Sonic 3 zones and for the most part it works the same way as using the codes above.

Level Differences

Flying Battery Zone

Sonic the Hedgehog 3 Sonic & Knuckles
Sonic3 Flying Battery.png SK Flying Battery.png

In Act 1, the mid-boss capsule is in a different position. In "Sonic 3C Prototype" is in the same position as Sonic 3.

Sonic the Hedgehog 3 Sonic & Knuckles
Sonic3 Flying Battery2.png SK Flying Battery2.png

It is possible to see that a line of rings were removed, perhaps the level design has been quite different in ACT1.

Sonic the Hedgehog 3 Sonic & Knuckles
Sonic3 Flying Battery3.png SK Flying Battery3.png

In Act 2, the location of the boss is very different.

Unknown Object Data

Object data of "Mushroom Valley Zone (ID 07)" can be found at these ranges:

Act 1: 0x0069A4A to 0x0069B4B
Act 2: 0x0069B4C to 0x0069C0B

The data mostly consists of a repeated pattern of path swappers, springs, and monitors, and an object with the number 93, which deletes itself once it's loaded, suggesting that these acts were once for testing.

Sonic 2 Options Menu


By setting the game's screen mode to $24, you can access the Sonic 2 options menu in Sonic 3! Alternatively, you can use the patch code FFF600:2400 or hack the menu back in yourself.

As all the options here are selectable normally through other means in Sonic 3, the only real benefit of this is entering the Sonic 2 level select code to access it in Sonic 3.


It's also possible to find the 2 Player Level Select from Sonic 2 using the patch code FFF600:1C00.

Unused Surfboard Intro


Sprites for an alternate intro sequence in which Sonic surfs onto Angel Island, rather than riding in on the Tornado. Interestingly, Sonic looks like his Sonic 2 incarnation, making this a fairly old leftover. The surfing Sonic sprite can still be placed in Angel Island Zone 1 via debug mode.


The sprites used when Sonic ditches the surfboard.

Unused Sprites



Sonic in his signature "waiting" pose, but instead of pointing towards the direction he's facing, he falls asleep from boredom. Interestingly, this animation was used for the version of Sonic Jam.


Sonic whistling. This was also used in the Sonic Jam.



A leftover animation from the Sonic 2 continue screen.



Unused gliding/climbing animations for Knuckles in 2-Player mode, despite him not having these abilities there (he uses Sonic's "temporary shield" ability, much like his single player "slot" uses Sonic). The recombined game, Sonic 3 & Knuckles, does not restore these functions (assuming they existed in the first place).


Sonic3eggmanpanic-running.gif Sonic3eggmanpanic.png

A set of sprites where Robotnik has a different facial expression.


Appears to be nothing more than Eggman flying away towards the horizon. There's actually an object that uses these sprites, but it's never called by any routine.

Mini Death Egg


A smaller rendition of the Death Egg that seems to be part of a Death Egg hologram projector, which itself was unused in Sonic & Knuckles.

Diagonal Penguin Sprites


Diagonal frames of the penguin badnik from Ice Cap Zone. These can be seen for a split-second if you place a penguin on the large hill at the beginning of Act 1 using debug mode.

Flying Battery Data Select Icon

Sonic 3 Flying Battery icon.PNG

A save file icon for Flying Battery Zone before it was re-ordered to be in Sonic & Knuckles, which is different than the corresponding icon in Sonic 3 & Knuckles. You can view this icon in the PC and Genesis versions by hacking the save data to access level slot $04, or by using PAR codes 00C324:601E 00C338:6002 to view it in a completed game save slot while scrolling through the levels.

(Source: Sonic Retro)

Ice Cap Intro Sprites


These graphics are loaded at the start of Ice Cap Zone 1. While the teleporter pad ended up being used in Sonic 3 & Knuckles for Knuckles' transition into the stage, the unusually oversized ice boulder was never used.

Act Clear Signs


In Sonic 3, the sign frames are uncompressed and loaded dynamically over each other to conserve video memory. This said, also present in the game's data is an unused copy of the same art compressed like in Sonic 2, strongly suggesting it is from earlier in development.

Although Sonic, Tails, and Robotnik are basically the same as their Sonic 2 counterparts, Knuckles appears for the first time, with a slightly different appearance relative to the final art. This early version is still present in Sonic & Knuckles.

Unused Music

To do:
List and upload the unused sound effects.

Music from Sonic & Knuckles can be played from the level select/sound test.

  • $09: Flying Battery Act 1

The loop point in the "echo" track of the lead instrument is set slightly later than the rest of the tracks; as a result, it falls further and further out of sync every time the song loops. This was fixed in Sonic & Knuckles and its lock-on.

  • $0A: Flying Battery Act 2
  • $0F: Mushroom Valley/Hill Act 1
  • $10: Mushroom Valley/Hill Act 2
  • $11: Sandopolis Act 1
  • $12: Sandopolis Act 2
  • $13: Lava Reef Act 1
  • $14: Lava Reef Act 2/Hidden Palace
  • $15: Sky Sanctuary
  • $16: Death Egg Act 1
  • $17: Death Egg Act 2
  • $18: Sonic & Knuckles Act 1 Boss (can be heard while fighting any Hydrocity Zone boss if you jump out of the water after the drowning music starts)
  • $1A: The Doomsday Zone
  • $1B: Glowing Spheres Bonus Stage
  • $1D: Slot Machine Bonus Stage
(Source: Sonic Retro)

Scrolling Credits

The game contains an unused, unfinished scrolling credits routine, which can be activated by setting RAM address FA87 to 2 during the credits sequence. The actual credits were apparently not yet in place when this was abandoned, as it scrolls small and large versions of the letters B-F, and then abruptly fades to the Sonic 3 logo screen. The final staff roll simply fades between static pages of text.


  • Like Sonic 2, all versions of Sonic 3 have both English and Japanese content (e.g. "Tails" for US/Europe, Miles for Japan). The content used depends on the console's internal region setting.
  • Knuckles' theme is just a set of drums that lasts for roughly two seconds, and loops forever. However, at around the 34-second mark is a brief voice sample before the next section of drums. This in and of itself isn't particularly interesting, but it should also be noted that whenever the song plays in-game it's always in scripted events; the song only ever plays for a maximum of 10 seconds or so. The only way to listen to this small sample is to use the sound test, jump just before the bridge collapses in the transition from Angel Island to Hydrocity and land on the piece of land that you fought the boss on and listen to it there, or wait after Knuckles bombs the building near the end of Launch Base Act 1.

Unused Enemies

  • Technosqueek: This Badnik later shows up in Sonic & Knuckles. For some reason, if you place a sideways one in debug mode, it crashes the game.
  • Blaster: Apparently is same as in Sonic & Knuckles, but it has a difference, their projectiles can be destroyed with a spin attack and it frees an animal.