Dr. Robotnik's Mean Bean Machine/Hidden content

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Sound test

MeanBeanMD SoundTest.png

If playing the game on a Japanese Mega Drive via patch code or a region switch hardware mod, a sound test will be available in the Options screen. The Game Genie code ADTT-AAAE will also make it appear but will trigger a checksum error if it is enabled before the Sega logo screen.[1]

Some of the songs in the sound test (specifically, 01, 0C, 0D, 0F, 10, 14, and 15) are hidden if the console region is set back to US. However, if the console region is still set to Japan, these tracks will get shown after the normally accessible tracks.

Checksum error


This game has the same checksum error screen from Puyo Puyo, and is triggered the same way. It is displayed at startup if the ROM's checksum fails.[1]

Bypass region lockout


When playing on an incorrect region system, the lockout screen can be bypassed by pressing A A Up Right Down Left B B Right Down Left Up C C Down Left Up Right Start Start on Controller 2. This code can only be attempted once; if a mistake is made, the system must be reset in order to try again.[2]

Unused content


Expectedly, there are multiple leftover graphical elements of the original Puyo Puyo game inside the game's memory (note: the sprite's original palettes from Puyo Puyo are used since the modified game does not feature matching ones):

Art Description
The cutscene sprites of the player character, Arle Nadja are mostly intact. They are still loaded with the cutscene unmodified, suggesting there were no plans in production stages for Sonic or any other player character to be utilised in Dr Robotnik's Mean Bean Machine.
The full tile set for the Lesson Mode arena is still inside the game (parts being utilised for the background of the Options screen and the Checksum Error message above). Curiously Lesson Mode itself does not load the area, implying it underwent some modification before being omitted altogether.
Some leftover tiles from the original high score screen.


There are a few unused songs and sound effects (mostly leftover from Puyo Puyo) and can be heard in the sound test.[1]

ID Description
01 A rendition of Kraftwerk's "Home Computer" that was removed for licensing reasons. This was originally the title screen music in an earlier build.[3]
0C Stage Clear jingle from Puyo Puyo.
0F Brave of Puyo Puyo. A remix of this is used in-game but this is the original arrangement.
10 Theme of Puyo Puyo. A remix of this plays over the credits, but this is the original arrangement.
14 Unknown. Perhaps a alternate warning music for the final stage.
15 A very weird sound.

Lesson stages

MeanBeanMD Lesson Coconuts3.png
MeanBeanMD Lesson.png
MeanBeanMD Lesson2.png

The Lesson stages from Puyo Puyo were not cut from the game and can be accessed by using PAR code 00BEFE:000? (? can be changed to 0-2). The tutorial text is glitchy and no music plays. Coconuts stands in strange positions in the stage cutscenes. Defeating the third Lesson stage advances the player to the ending cutscene.[1]

Cheat device codes

These are cheat codes that can only be used with game enhancer devices. Support for these codes is available in most emulators.

Game Genie

Official codes

Code Effect Reference
ALNT-AA66 Refugee beans are disabled.
VWNT-AAHE Refugee beans come in smaller amounts.
ERNT-AAHE and/or C8NT-AAHE Refugee beans come in larger amounts.
AW9A-AAH8 Start on Scenario mode Stage 2.
A09A-AAH8 Start on Scenario mode Stage 3.
A49A-AAH8 Start on Scenario mode Stage 4.
A89A-AAH8 Start on Scenario mode Stage 5.
BC9A-AAH8 Start on Scenario mode Stage 6.
BG9A-AAH8 Start on Scenario mode Stage 7.
BL9A-AAH8 Start on Scenario mode Stage 8.
BR9A-AAH8 Start on Scenario mode Stage 9.
BW9A-AAH8 Start on Scenario mode Stage 10.
B09A-AAH8 Start on Scenario mode Stage 11.
B49A-AAH8 Start on Scenario mode Stage 12.
B89A-AAH8 Start on Scenario mode Stage 13.

Unofficial codes

Code Effect
ALNT-AA66 Refugee Beans Are Disabled.
CBNT-AAHE Refugee Beans Come In Gargantuan Amounts.
VWNT-AAHE Refugee Beans Come In Smaller Amounts.
ADTT-AAAE Unlock sound test.

Action Replay

Unofficial codes

Code Effect
FFE166:?? Player 1 - Falling Bean Color Modifier (Bottom Bean)
FFE167:?? Player 1 - Falling Bean Color Modifier (Top Bean)
  • 00 - Red
  • 01 - Yellow
  • 02 - *Glitch*
  • 03 - Green
  • 04 - Purple
  • 05 - Blue
  • 06 - Unbreakable Bean
FFE226:?? Player 2 - Falling Bean Color Modifier (Bottom Bean)
FFE227:?? Player 2 - Falling Bean Color Modifier (Top Bean)


Dr. Robotnik's Mean Bean Machine (16-bit)
Mean Bean title.png

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