Comment by KeplerBoy

You can do pretty much anything if the cartridge is advanced enough. At that point you just output a framebuffer from the cartridge the screen should show with no computation happening on the actual gameboy CPU.

People built cartridges which stream game footage from a PC to the gameboy and relay the inputs back to the PC to "play" GTA 5 on an original gameboy. https://www.youtube.com/watch?v=pX1opw_gsBs