The Game Boy Color never got a game from the Wolfenstein series. However, a modder decided to take matters into his own hands and started working on a playable version of Wolfenstein 3D for the Game Boy Color with a boosted cartridge.
A classic from 1992
Released in 1992 for MS-DOS and later adapted to SNES, Mac OS, Jaguar, 3DO, and Game Boy Advance (among other platforms), Wolfenstein 3D put players in the role of William "B.J." Blazkowicz, an Allied spy who must escape a Nazi fortress. This time, modder Anders Granlund built a playable version of Wolfenstein 3D on Game Boy Color with a boosted cartridge. To give you an idea of the difficulty, Granlund designed and built a custom board with ARM to feed graphics and incorporated it into the cartridge.
Custom hardware
On Granlund's official site you can see in detail the procedure he followed (with videos and photos) to achieve a playable version of Wolfenstein 3D on Game Boy. To carry out the project, Granlund used a board to program the EEPROM itself, and then ordered a custom board with pinouts. Using those, he added an NXP graphics processor equipped with an ARM Cortex-M0 running at 48MHz. That chip is obviously more powerful than the Intel 386 CPU that originally ran Wolfenstein on MS-DOS. Once everything worked, Granlund ordered another custom board combining his original design and the NXP processor.
Playing on original hardware
After some tweaks, everything started working as expected, powered strictly by the Game Boy Color's batteries. This is the fifth playable version of Wolfenstein 3D on Game Boy, and it works incredibly well on the 160 x 144 pixel screen, as you can see in the video, although for now it only has three types of enemies and the ten levels of the first episode. This isn't the first time we've seen adaptations of this kind; earlier this year a user developed Wolfenstein 3D in 600 lines of code in the AWK language, and the old Doom has been run in very strange places, from calculators, ATMs, a printer, and even on the Touch Bar of the new MacBook Pro. And going further, Wolfenstein 3D was adapted to Game Boy Advance directly from the MS-DOS version.
