Marble Madness (Game Boy Color)

Marble Madness
Developer: Digital Eclipse Publisher: Midway Games Platform: Game Boy Color Released in US: December 1, 1999 Released in EU: March 13, 2000 This game has unused code. This game has hidden development-related text. This game has unused modes / minigames. This game has unused graphics. This game has unused text.

Marble Madness is a lackluster port of the arcade game of the same name, with worse controls and music, and no two-player support.

Build Date

Located at 0x01 is a build date.

Date 991231

Unused Graphics

An earlier Digital Eclipse logo is present at offset 0xC0BAC, and is loaded into VRAM at address 0x30:0x402A. However, the corresponding tile map indexes are not present in the ROM, and the top part of the graphics was overwritten by the used logo.

Graphics for selecting 1 player / 2 players are present at offset 0xD229, and are loaded into VRAM at the "Roll marble to choose" screen.

Lost 2 Player Mode

Marble Madness has an unfinished two-player mode. The red marble was fully programmed and behaves the same as the blue marble. Game Genie code 0D0-348-C4A will load the two-player link screen directly after the Midway logo starting a race. The game will return to the main menu if an error occurs with the link connection for either player. There are a few things worth noting about the unfinished two-player mode:

• Player 2 (Red) has a blue timer.
• After player 2 completes a race, the goal will be blue.
• The second player will not be able to enter their score.
• When either player runs out of time, they will be booted to the main menu and the race will continue for the other player.

Game Genie code 00F-B8B-E62 will trigger the placeholder link screen as soon as the first level begins. Neither linked Game Boys will communicate. The reset game function works as intended when Select button is pressed.

Text for the unused two-player mode can be found at 0x535C. It includes a warning message when resetting the game, although it never gets shown. It's possible to force this warning screen to load instead of the "Link error" screen. Function 0x01:0x432D loads an offset table stored at 0x01:0x4801 with entries for each message screen. The index for this table is stored in memory at 0xC25A, and the index is set at address 0x00:0x0AF9 with value 7, corresponding to the "Link error" screen. Game Genie code 08A-FAF-F76 will load value 8, corresponding to the "Game reset" warning screen.

(Source: nensondubois, QUFB)

Unused Reset Message Screen Function

Function 0x00:0x13C5 contains logic to display a message screen then wait for A+Select to be pressed to reset the game. This particular input doesn't match any of the existing messages. Game Genie code C5B-00F-7F1 can be used to replace the call at address 0x00:0x0AFF to instead call this function.

Unused No Input Message Screen Functions

Function 0x00:0x1405 blanks the screen, and function 0x00:0x1422 displays a message screen without waiting for any player input. Although some message screens fit with this logic, these functions have no call references. These can be manually run with a debugger, by setting a breakpoint at address 0x00:0x13E6, then setting the program counter to one of the addresses described above.

Unused Demo Messages

There are only two demos and forcing either to play for longer will still refuse to display either message. GameShark code 01??ADCA will display the selected message in place of the current level starting text.

Unused Demo Message 1

ID 09

may have told the player to avoid being slow.

Unused Demo Message 2

ID 0A

not sure what this is for, as no marble munchers appear in the first level

Planned Game Boy Printer Support

Located at 0x49ED is unused text for an option to print high scores. There is no programming code to print out the high scores, but the message screens are still present. These can be loaded using the same approach as the "Game reset" screen, by applying Game genie codes 0D0-348-C4A and one of the following for each screen:

• 01A-FAF-F76
• 02A-FAF-F76
• 03A-FAF-F76
• 04A-FAF-F76
• 05A-FAF-F76
• 06A-FAF-F76

Alternate GBC Only Message

An alternative message screen can be loaded using the same approach as the "Game reset" screen, by applying Game genie codes 0D0-348-C4A and 00A-FAF-F76.

This message's text can be found at offset 0x4884.