Homebrew software developer Anders Granlund produced a playable Game Boy Color version of Wolfenstein 3D using a custom game board fitted with a co-processor chip, he has documented his build on his website here.
The results are decent and more important, playable, especially considering that the game fits into 128k (currently at 123k!) of memory and runs smoothly on hardware that is only slightly more powerful than the 8-bit NES.
Wolfenstein 3D has been ported to multiple home consoles in its heyday, including the 3DO and Atari Jaguar. A heavily censored port later made its way to the 16-bit SNES, removing the original game’s blood and gore in addition to exchanging its German Shepherd enemies for giant mutant rats, then onto the GBA and of course every hacked, modified and ‘homebrewed’ box inbetween, whilst the GBA’s hardware is capable of powering Wolfenstein 3D on its own, the same can’t be said of its predecessor, the Game Boy Color.
Granlund faced difficulty in porting a 3D first-person shooter to an 8-bit platform with a maximum display resolution of 160 x 144 pixels, leading him to craft a custom game board featuring a KE04 co-processor, an AM29F040 EEPROM, and an MBC1 memory mapper salvaged from a mass-produced Game Boy game.
Things like this may seem small and trivia, but some of the best works are formed from a small little hack and ploy and we get REALLY excited at the Arcade Punks offices at things like this 😀