Sonic Mania

Sonic Mania
Also known as: Sonic Mania Plus Developers: Sega, Christian Whitehead, Headcannon, PagodaWest Games, Tantalus Media (Switch), Lab42 Games (Android/iOS) Publishers: Sega, Netflix (Android/iOS) Platforms: PlayStation 4, Nintendo Switch, Xbox One, Windows, Amazon Luna, Android, iOS Released internationally: August 15, 2017 (PS4/XB1/Switch), August 29, 2017 (Windows), July 17, 2018 (Plus), May 7, 2024 (Android/iOS) Released in US: October 20, 2020 (Luna) Released in AS: February 14, 2024 (Android, Philippines) This game has unused animations. This game has unused areas. This game has hidden development-related text. This game has unused enemies. This game has unused objects. This game has unused graphics. This game has unused models. This game has unused music. This game has unused sounds. This game has debugging material. This game has a hidden sound test. This game has a hidden level select. This game has revisional differences. This game has a development article This game has a prerelease article This game has a bugs page

After almost 23 years, classic Sonic gameplay returns in all its 2D pixel-perfect glory. Designed as if it were a Sega Saturn followup to the Genesis-era titles, Sonic Mania features a mix of brand-new stages and remixed classics, with a hearty dose of references to other Sonic games, other Sonic media (there's a nod to the OVA in here!), and other Sega stuff in general. It also launched with a game-breaking SteamAPI-Denuvo conflict bug on PC, which didn't go down well to say the least.

In 2018, the game received an upgrade/DLC expansion in the form of Sonic Mania Plus, adding the long-absent Mighty the Armadillo and longer-absent Ray the Flying Squirrel as new playable characters, a special Encore Mode, a physical release with an artbook and reversible Genesis/Mega Drive cover for added nostalgia points, and other goodies.

All things considered, it's perhaps only fitting that there's a crapton of unused stuff in here.

To do: A decompilation of the game has been released. Check for any unused bits of code and oddities.

Sub-Pages

Development Info

Prerelease Info

Bugs

Unused Graphics Scrapped Brain Zone.

Hidden Areas Robotnik's secret hidey-holes.

Revisional Differences Revised bosses, added transitions, and more!

Level Select and Debug Mode

Place the cursor on the "No Save" portion of the file select menu, hold one of the following buttons/keys according to your version, and press Start. However, Debug Mode (which can be unlocked by collecting at least 16 medals from the Blue Sphere bonus stages) must be enabled for this code to work. In v1.03 of the Switch version, you can also access the Level Select from the title screen by holding Y and pressing any other button.

Platform	Button
PlayStation 4	◻ (Square)
Switch	Y
Xbox One	X
PC	Q + A (on the keyboard)

Controls for this screen are as follows:

• D-Pad / Arrow Keys: Navigate through the menu.
• ◻ (PS4) / Y (Switch) / X (XB1) / Q (PC): Switch between Sonic, Tails, and Knuckles (and if playing the Plus version, Mighty and Ray) as the player character.
• △ (PS4) / X (Switch) / Y (XB1) / W (PC) when Sonic is selected as the player character: Toggle Sonic & Tails.
• ◯ (PS4) / A (Switch) / B (XB1) / A (PC): Play highlighted level/selected Sound Test entry.

Debug Mode is automatically enabled through this menu.

As of v1.03, controls for debug placement mode are as follows:

• ◻ (PS4) / Y (Switch) / X (XB1) / Q (PC): Enable/disable debug placement mode.
• ✕ (PS4) / B (Switch) / A (XB1) / A (PC): Cycle forward through the available objects.
• △ (PS4) / X (Switch) / Y (XB1) / W (PC) while holding the above button: Cycle backward through the available objects.
• ◯ (PS4) / A (Switch) / B (XB1) / S (PC) when selecting an item monitor: Change the item monitor's contents.
• D-Pad / Arrow Keys: Move currently selected object around.
• △ (PS4) / X (Switch) / Y (XB1) / W (PC): Place currently selected object.

A set of debug coordinates also appear at the top-right corner of the screen when debug placement mode is active. The top 8 digits are the X and Y coordinates of the camera, while the bottom 8 digits are the X and Y coordinates of the player.

(Source: unAWARE777)

Retro Engine v5 Developer Menu

Standard / Without Data Folder	w / Data Folder

In the PC version, by adding "devMenu=1" or "devMenu=y" to the "[Game]" section of Settings.ini, and pressing the ESC key in-game, a hidden developer menu is displayed.

You can also enable the Dev Menu by extracting the contents of Data.rsdk into a folder named "Data", placing it into the Sonic Mania installation folder, and removing the Data.rsdk file or altering the file name. Doing this will also change the GameConfig.bin header to display "Sonic Mania (Data Folder)" text in the Dev Menu and on the game's window title bar along with accessing Data Folder mode.

• Resume: Exits the Dev Menu and returns you to wherever you were before opening it. For some reason, selecting this will also prevent whatever music track playing beforehand from resuming playback. Pressing the ESC key again when viewing the Dev Menu will not only serve the same purpose as this option but will also bypass the music issue, and it can also restore the intended music track to start playback again if you used the resume option beforehand.
• Restart: Instantly restarts the scene/stage you were in before opening the Dev Menu. This option can also instantly display changes made to a scene/stage you have edited instead of having to close the game and reopen it. This can also restart gameplay from the last starpost/checkpoint you passed in-game, even works with ones you're able to place in debug mode.
• Stage Select: Goes to a sub-menu with the following options:

• Presentation: Small scenes related to starting and ending the game.

• Logos: Developer logo splash screen.
• Title Screen: It's the title screen. Wow!
• Menu: Goes to the main menu, in case this dev menu isn't exciting enough for you.
• Thanks For Playing: An otherwise unused screen that would've been displayed at the end of public/media outlet demos, however, the graphics seem to be absent. For some reason, if you apply unlock codes for the "UI Decoration" object utilizing the Mania Mod Manager, the graphics appear and the screen functions as intended.

Vanilla	Restored

• Level Select: Jumps to the fancier Level Select screen mentioned previously.
• Credits: Goes to the credits.
• Continue: Continue screen seen in the No Save mode. By default, it plays the Sonic & Tails continue screen. Simply pressing the "Jump" button (default A) will let you play as Sonic alone, holding "Back" button (default S) and then pressing "Start" (default Enter) will let you play as Tails, and holding "Delete" button (default Q) and pressing "Start" will let you play as Knuckles. This is also the only known way to change character without using a save file or restarting from the beginning.
• Game Summary: The player's statistics which are displayed at the end of Mania Mode (as of RC 1.05.0713).
• Encore Summary: Same as above, but for Encore Mode (as of RC 1.05.0713).

• Media Demo: Used to showcase two different Zones to various media outlets (has been removed as of RC 1.05.0713). Those Zones were:

• Green Hill Zone 1: Uses the same scene file as the main game, but all Big Rings are deactivated. Leads directly into Studiopolis Zone 1 with no fade-out.
• Studiopolis Zone 1: This level uses a completely separate scene file - Scene1D.bin as opposed to Scene1.bin as in the main game. This scene contains a good amount of layout differences to the final version. The Music entity is trying to play "SPZ1.ogg", a file that no longer exists, so the level has no music. If the player does anything to cue new music (like hitting an Invincibility Monitor or reaching the end of the Act), the game will crash. If the correct music track is added back in via modding, once the Act is done the game immediately goes back to the title screen after the score tally has completed.

• Mania Mode: A text-based stage select for Mania Mode. There are two entries that aren't in the normal stage select:

• Stardust Speedway Zone 2M: The area used for the Metal Sonic fight.
• Titanic Monarch Zone 3: The final boss area.

• Encore Mode: A text-based level select for Encore Mode. Disabled if the Encore DLC is not installed.
• Special Stage: Play any of the fourteen Special Stages.
• Blue Spheres: Play any of the 32 Blue Sphere stages. Also includes a "Random" and "Random 2" option. Random 2 will use the "Mania Mode" of the Blue Sphere stages, which adds new spheres with different effects.
• Pinball: Play the Pinball Bonus Stage. Strangely, this can be accessed even if the Encore DLC is not installed.
• Extras: Includes the unlockable Puyo Puyo mode and the D.A. Garden.
• Cutscenes: These are the in-game cutscenes, not the animated ones.

• Angel Island Zone: The cutscene at the start of Mania Mode.
• Angel Island Zone Encore: The short playable Act of Angel Island Zone at the start of Encore Mode. This can be accessed without the Encore DLC, but bugs will occur.
• Green Hill Zone: The cutscene immediately after the AIZ cutscenes before Green Hill starts. Strangely this scene contains unviewable, early level design of GHZ act 1 further discussed below.
• Green Hill Zone 2: The cutscene at the very end of Act 2. Also includes early level design for GHZ act 2, discussed below.
• Mirage Saloon K Intro: Knuckles gets knocked off the Tornado. Oh no.
• SSZ Time Warp: The time-traveling cutscene seen at the end of Stardust Speedway Act 1.
• Try Again: Eggman taunts you and your lack of Special Stage skill.
• Mirage Saloon Encore End: The final cutscene played in Encore Mode's true ending.
• Try Again Encore: The Heavy King taunts you and your lack of Special Stage skill.

• Videos: All of the game's animated endings. The Knuckles & Knuckles ending is labeled as "True End?"

• Options: Change game settings.

• Video Settings: A few extra video options.

• Window Size: Options are 1x, 2x, 3x, and 4x. In the normal video menu, this only goes up to 3x.
• Window Aspect: Missing from the normal Video menu. Options are 16:9, 4:3, 3:2, 16:10, and 5:3.
• Fullscreen: A simple YES/NO choice.
• Screen Shader: The same options as the normal Video menu, except CRT-Sharp is named "CRT-Yeetron" and CRT-Soft is named "CRT-Yee64".

• Audio Settings: Volume slides, plus a "Streams Enabled" option that when set to "NO" will prevent any more music from playing.
• Configure Input: Configure those inputs!
• Debug Flags: Allows you to enable or disable layers and sprites. This option only appears in RC 1.05.0713 onwards. You can always enable Debug Mode anywhere.

• Exit: Exits the game.

Activating the Dev Menu will also activate some other developer features. Holding Backspace will fast-forward the game, and pressing F12 will immediately freeze or unfreeze the game. While the game is frozen with F12, F11 will advance it one frame at a time. If used on Steam, this will disable the screenshot function if the key is bound to F12.

(Source: RibShark)

As of v1.05, while in a Special Stage, pressing the Super button will advance the player one mach. You can do this infinitely. Strangely, this does not require the debug menu or any cheats to be enabled in order to work, meaning one can easily stumble upon it accidentally in a normal playthrough, though it still only works in the PC version.

Version Numbers

Platform	Version Number
Switch (eShop base title)	RC 7/17/17
Steam (App ID: 584400, Manifest ID: 8730961330600092468, 4586700242215819845)	1.03.0829
Steam (App ID: 584400, Manifest ID: 2423105704892348622)	1.03.0831
Steam (App ID: 584400, Manifest ID: 3856100003260477365)	1.03.0919
Steam (App ID: 584400, Manifest ID: 1422308210609141148)	1.05.0713
Steam (App ID: 584400, Manifest ID: 5356543651121673626)	1.05.0713
Steam (App ID: 584400, Manifest ID: 8440811224789314446)	1.06.0503
Epic	1.07.0022
Origin	1.07.0033
Android	1.07.0035

These are the version numbers used in the debug menu. They are contained within GameConfig.bin.

(Source: Original TCRF research)

Mania/Encore Swap Cheat

Via setting Sonic Mania's internal platform ID to 255 (corresponding to "dev"), the ability to switch between Mania/Encore Mode seamlessly becomes available to the player by pressing the key/button mapped to the "Z Button", however due to the way Sonic Mania handles stage palettes when switching back to Mania Mode, the Encore Mode palette will show instead of the Mania one. It uses the Super and Hyper transformation sound from Sonic 3 & Knuckles.

Collision Viewer

Using Debug Mode, choose the "S" object and place it on the map. The terrain will be highlighted in different colors, indicating the solid terrain:

• Yellow - Tiles that are solid from the top. Used for platforms.
• Red - Tiles that are solid from the bottom and sides. Usually for walls and ceilings.
• White - Tiles that are solid all over. Usually for the ground.

Camera Movement Mode

This mode can be found if you use Debug Mode with Tails in Mirage Saloon in Sonic's Act 1. Place a signpost; then, if you're lucky, you will be taken to Knuckles' Act 1 and the mode will be activated.

This "mode" is activated when no characters can be loaded, as seen in Sonic & Tails in Knuckles' Mirage Saloon Zone Act 1. As the player object is only set to load Knuckles, and not Sonic or Tails, no characters are loaded in.

The controls are as follows:

• ✕ (PS4) / B (Switch) / A (XB1): Increase movement speed of camera if held.
• D-Pad: Move camera.

(Source: yoshikirby43)

Unused Objects

To do: There are more objects hidden in the game. Also, add pictures for some of the listed objects below.

Title Screen

An object intended for the Media Demo that can be found in the title screen named DemoMenu (that has to be manually added to StageConfig.bin).

You can find the decompiled code of this object from the Sonic Mania Decompilation here and here.

Selecting one of the 2 options will find a menu category named Media Demo and looks for the scene Green Hill Zone 1 or Studiopolis Zone 1 (which will loop you back to the first scene since the whole category was removed for Plus).

Green Hill Zone

The original version of Splats can be placed with Debug Mode in both Acts, separate from the updated Splats used in Press Garden Zone Act 1. This version of the badnik uses its original unused sprites from Sonic 1 with no modifications, suggesting this badnik was scrapped early if it was ever seriously considered for inclusion in the Zone. Since the artwork hasn't been redrawn to account for the updated palette it displays incorrectly, with the lightest tan shade replaced with grey and one of the blue shades overwritten by one of the cycling colors used by the Zone's animated waterfalls. Interestingly, this version of Splats behaves differently compared to either version found in the Debug Mode of the original game's 2013 remake, suggesting this is more than just a carried-over leftover.

You can find the decompiled code of this object from the Sonic Mania Decompilation here and here

The rolling ball can also be placed with Debug Mode. This functions identically to the version in the original game's 2013 remake, though it doesn't use the exact same graphics. You can find the decompiled code of this object from the Sonic Mania Decompilation here and here

Press Garden Zone Act 1

Graphics for Act 2's Woodrow badnik are loaded in Act 1's enemy sheet. The only enemies which normally appear in both Acts are Dragonfly and Juggle Saw, Splats is exclusive to Act 1's sheet, and Carry is exclusive to Act 2's, so Woodrow's presence in both implies it was intended for both Acts at some point.

Lava Reef Zone

Two objects that appeared in the original level are unused here, with updated sprites:

• LavaFall - a stream of lava that falls from the ceiling.
• TurretSwitch - a turret enemy that fires bullets when Sonic is near and activates a door when destroyed.

Interestingly, both of these objects are used in the early version of Act 1 found in LRZ's stage folder. They can also be found in the stage's debug list.

You can find the decompiled code for these objects in the Sonic Mania Decompilation here with their respective names for the objects.

Metallic Madness Zone

Caterkiller, taken directly from Sonic 1. Caterkiller isn't in the stage's debug list - it has to manually be added to StageConfig.bin. Because its sprites are located with the sprites for Metallic Madness, it is safe to assume it was meant to appear here.

Misc.

• Monkey Dude from Sonic 3's Angel Island Zone. It has smoother animations than the original, but doesn't seem to behave properly - you can't destroy it, nor can it damage you or throw its coconut. A completed version of this badnik was later implemented in v1.05 for Encore Mode's Angel Island Zone.
• Whisp from Sonic 2's Aquatic Ruin Zone. Behaves the same as the original.
• The spear blocks from Sonic 2's Metropolis Zone. Behaves the same.
• The colored pins from Sonic 2's Casino Night Zone. Behaves the same, minus sound effects.

All of these objects use sprites from the now-absent Blueprint folder. The folder must be re-added for the objects to display properly. These objects are also not present in any of the stage's StageConfig - they must be added manually.

Unused Models

To do: The models have vertex colors. The previews need to be changed with colorized models. Wireframe mesh of Eggman's Mech appears at the end of Stardust Speedway Act 2 in Sonic Mania Plus. Needs to be compared with leftover model.

Name	Artwork	Comment
MonarchBG		Located in Data\Meshes\TMZ\ is an unused 3D model of the Mech seen in the background of Titanic Monarch Zone. According to Stealth, it was converted into a 2D image to be used in the final game. (Source: Stealth)
Sonic		Located in Data\Meshes\Global\ is the 3D Sonic model from Sonic Jam, likely used as a reference at some point. It's also possible that the developers were going to use this model in Special Stages instead of creating a whole new model.

Unused Audio

Music

This track is listed in the D.A. Garden as "Egg Reverie Pinch Mode", which suggests that Egg Reverie Zone would have had two phases, but was scrapped. This track is listed as 2A in the Sound Test/Level Select.

In the official "Selected Edition" soundtrack released to digital storefronts, the track is given the name "Egg Panicky" and is noted to be only available through the Sound Test.

Sound Effects

Name	Sound	Notes
Global/Sliding.wav
Stage/Beep.wav		Files Stage/Beep3.wav and Stage/Beep4.wav are used, but these two are not.
Stage/Beep2.wav
Stage/Ducc.wav		A joke sound effect that sounds like a duck quacking.
Stage/Electrify2.wav		While Stage/Electrify.wav (taken from Sonic 1) is used, this sound (taken from Sonic CD) isn't. This is pretty much just a lower-pitched version of Stage/ElecCharge.wav (also used) anyway.
Stage/LedgeBreak2.wav		There are three different "ledge breaking" sound effects in the game. This is the one that isn't used.
Stage/Rev.wav		Technically, this sound effect is used by the Stegway badnik, but said badnik is also unused.
Stage/Strain.wav
Stage/Swing.wav		Basically the same sound as SSZ1/Flail.wav, but this version is 0.4 KB larger for some reason.
CPZ/Sticky.wav		The original sound effect for the sticky platforms in Chemical Plant Zone. The final game uses Puyo/Land.wav to reinforce the Dr. Robotnik's Mean Bean Machine connection.
FBZ/SpiderBounce1.wav		Three sounds meant to play when the Spider Mobile is being bounced around the arena.
FBZ/SpiderBounce2.wav
FBZ/SpiderBounce3.wav
MSZ/RkillerRattle.wav		This would have been a sound that was meant to be played when around the Rattle Killer Badnik.
TMZ1/HogBounce.wav		This was probably supposed to be used when the Ball Hog's projectiles bounce off the ground.

Early Sound Effects

Earlier versions of existing sound effects left in the game. The early versions of the Grow and Shrink sound effects are the same ones used for the identically-named power-ups in Knuckles' Chaotix.

Early Sound		Used Sound		Context
Stage/RingO.wav		Stage/Ring.wav		An original sound effect for gathering rings.
Stage/Warp.wav		Stage/Teleport.wav		Using a teleport box in 2P mode.
MMZ1/Grow.wav		MMZ1/Grow2.wav		Hitting a growth ray while shrunk in Metallic Madness Zone.
MMZ1/Shrink.wav		MMZ1/Shrink2.wav		Hitting a shrink ray at full size in Metallic Madness Zone.
SSZ2/MSTransform1.wav		SSZ2/MSTransform.wav		Metal Sonic's transformation into Giga Metal Sonic.

I'm Outer Here!

Screenshot	In-Game Restored

A callback to Sonic CD, Sonic says "I'm outer here!" and jumps offscreen, causing an instant game over. According to a developer, this was in pre-release demos but was disabled in the final game, probably for the demo to restart after the player leaves the game for too long. To activate it, edit the RAM memory at address 0A4D667 and change the value to 10. In the decompilation, the way they disabled it is by setting the timer for the animation at 333 hours, which equates to 19,980 minutes or about 13.9 days!

Interestingly, this can also be activated with Tails and Knuckles, though the outcomes differ: Knuckles will be swapped with various parts of his spritesheet and jump offscreen, causing a game over, while Tails' sprites also flip out to different parts of his spritesheet, but does not jump offscreen.

Since it was only used in the demo, it may be possible that Tails and Knuckles were never supposed to use this behavior, because most of the demo is only Sonic on the Player 1 spot (Tails was later playable in the Switch demos, but only as Player 2). And the sprite was not allocated to do that, causing the sprites to freak out.

In v1.05, the animation is used on the main menu when scrolling over the "Exit" option in the PC version.

In Plus, Ray will jump as soon as he says "I'm outer here" while Mighty takes longer than everyone else. Interestingly, Mighty and Ray don't become a mess of sprites and instead use the sixth frame of their climbing animation for FBZ. Ray jumps into the background, and Mighty jumps forwards.

This voice line is commonly heard as "I'm outta here!". Masato Nishimura, a designer at Sega and the voice of Sonic in Sonic CD, stated on Twitter in July of 2017 that the intended spelling for the line is "I'm outer here!", as shown in his Twitter post.

Unused Text

The following strings are present in all language packs, but are always in English.

TEST STRING

A simple test string.

THIS FEATURE IS NOT
YET IMPLEMENTED

Obviously intended for work-in-progress versions.

PLACEHOLDER...
SIMULATE LOG IN?

This was probably used when trying to submit Time Attack scores before they were properly set up.

By the Mania for the Mania

GameConfig.bin contains the game's tagline alongside text used in the developer menu.

(Source: Original TCRF research)

This is a game dawg!

The Switch version uses this phrase instead of the previous string.

(Source: Axanery (Twitter))

Development Text

Platform	Text
Switch (eShop base title)	E:\ProjectsPerforce3\Sonic\active\branch-dev\NX64\Release\Sonic Mania NX.nss
Steam (App ID: 584400, Manifest IDs: 8730961330600092468, 4586700242215819845, 2423105704892348622, 3856100003260477365)	C:\Users\TaxmanRMBP\Documents\Visual Studio 2015\Projects\SonicManiaSKUs\Release\SonicMania.pdb Protected.pdb
Steam (App ID: 584400, Manifest ID: 1422308210609141148)	D:\SonicMania\SM_Source_2018-04-09-Re\discovery-skus\Release\SonicMania.pdb SonicMania.pdb
Steam (App ID: 584400, Manifest ID: 5356543651121673626)	D:\SonicMania\SM_Source_2018-04-09-Re\discovery-skus\Release\SonicMania.pdb SonicMania_devmenu.pdb
Steam (App ID: 584400, Manifest ID: 8440811224789314446)	D:\SonicMania\sonicmania\SM_Source_2018-04-09-Re\discovery-skus\Release\SonicMania.pdb
Epic	D:\Sonic_AS\SM_Source_2018-04-09-Re\discovery-skus\Submission\SonicMania.pdb
Origin	D:\SonicMania\SM_Source_2018-04-09-Re\discovery-skus\Submission\SonicMania.pdb

The executable of each build contains pdb file paths and filenames.

(Source: Original TCRF research)

Early Levels

Green Hill Zone Act 1

An early Green Hill level design, similar to what was presented in the San Diego Comic Con demo, is located in the GHZCutscene folder in the file Scene1.bin. This is used for when the Phantom Ruby teleports you to Green Hill Zone in the intro, with the actual level being loaded afterwards.

Early	Final

A hidden alcove with a Giant Ring that was removed from the final version. It's obvious that it's there, though, with that bit of grass sticking out from behind the wall.

Early	Final

The upper-left secret area houses a Giant Ring in the demo, and is accessible by pushing a rock; however, this was moved to the right side of the section for the final game, where it instead holds nine rings and a 1-Up monitor. An S tunnel was removed in the process. The Giant Ring was moved down, making it easier to find.

Early	Final

A secret area, most likely intended to hold a giant ring, was removed, as was a platform on the wall above the run-down ledge. The early area with a giant ring was re-implemented in Encore Mode. But interestingly, the area can now be found in the Mania Mode version of the final, only blocked off and inaccessible.

Early	Final

Some areas of the lake appear incomplete. On the right side of the waterfall is a secret area, which was also probably meant to contain a giant ring.

Green Hill Zone Act 2

An early level can be found in Scene2.bin in the GHZCutscene folder, used as a cutscene after defeating the Death Egg Robot. There are no major changes in the final version, just visual touch-ups. The full map can be seen here.

Studiopolis Act 1

To do: A comparison may be needed for this one.

Using the Dev Menu before Sonic Mania Plus / v1.04+, going to the Media Demo section and selecting Studiopolis Act 1 will take you to an early version of said Zone, which is very similar to the one that was playable at PAX 2016 and early demos. It is accessible after v1.04+ by swapping Scene1.bin with Scene1D.bin in the SPZ1 folder.

Lava Reef Zone Act 1

An early playable Lava Reef Zone Act 1 is accessible by swapping Scene1.bin with Scene2.bin in the LRZ1 folder. It is comprised of sections from the original Sonic & Knuckles stage alongside sections that were used in Mania, albeit with incorrect graphics. It also makes use of the unused turrets and lavafalls not seen in the finished level. The background music plays incorrectly due to an improper loop point. The boss appears and works normally.

Angel Island Zone Act 1

A ported file from Christian Whitehead and Simon Thomley's Sonic 3 & Knuckles Retro Engine version appears as AIZ/Scene1O.bin. The level includes all of the original layout, although with different graphics due to the tile sheet having the tiles in different locations.

Angel Island Zone Act 2

To do: Split the attached image up into multiple parts. It's too big for a preview.

Another ported file from Christian Whitehead and Simon Thomley's Sonic 3 & Knuckles Retro Engine version appears as AIZ/Scene2O.bin. Like Act 1, this Act also appears with different graphics due to the different tile locations.

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Angel Island Zone Test Level

AIZ/Scene3.bin is a test level for cutscenes, enemies, and gimmicks for Angel Island Zone.

Filename Oddities

Chemical Pools in Chemical Plant Zone Act 2

The names for the chemical pools in CPZ Act 2 reveal that the colors were changed: ChemRed.wav is used for the green chemical pools, and ChemYellow.wav is used for the cyan chemical pools. This could also refer to red and yellow springs, respectively, which both of these elements behave like.

Pulp Solstice Zone

Press Garden Zone's music files are internally called PulpSolstice1 and PulpSolstice2, and its sprite folders are called PSZ1 and PSZ2. This suggests that the Zone was once called Pulp Solstice Zone.

Tuesday?

The internal name for the electrical conduits in Flying Battery Zone Act 2 is, confusingly, "Tuesday". Funnily enough, the release dates for Sonic Mania (August 15th 2017) and Sonic Mania Plus (July 17th 2018) are on Tuesday.

Heavy Magician

Most internal references to Heavy Magician refer to her by the alternate name of "HeavyMystic", while the version encountered during the boss of Titanic Monarch Zone Act 2 is "PhantomMystic", indicating that the character's official name was changed at some point.

This is further supported by Stealth accidentally referring to her as Heavy Mystic instead of Heavy Magician during a livestream.

Cut Bonus Stages

There are four unused Blue Sphere stages in the game. They cannot be accessed through the DevMenu; the only way to load them in-game is by renaming their SpecialBS files.

Name	In-Game	Map	Comment
Scene33			This is a test level, composed of a large area full of blue spheres and a cross-shaped line of red spheres. It is impossible to get a Perfect here.
SceneTest3			All of these stages appear to be complete, but go unused for whatever reason.
SceneTest7
SceneTest8

(Map rips: Random Talking Bush)

Unused Mania Mode Dioramas

In Sonic Mania Plus / v1.04+, there are two unused Mania Mode Dioramas in the game. Dioramas 00 and 02 are completely unused, yet are quite similar to the one that is actually used.

They can be accessed through the Dev Menu by going into the options, then selecting Debug Flags. There, you will be able to alter the Diorama to the two unused ones.