rgbds

Public domain Tetris ROM to try it: https://github.com/tbsp/Adjustris https://github.com/tbsp/Adjustris/releases Another one, a platform game, GPLv3 licensed: https://github.com/mholtkamp/carazu https://github.com/mholtkamp/carazu/releases You need this to compile both ROMs: https://github.com/gbdev/rgbds

Game Boy disassembler: https://github.com/mattcurrie/mgbdis You can compile the ROM's back with rgbds: https://github.com/gbdev/rgbds Here you can see how bank switching works. Also, recent versions of file(1) from Unix can parse GB ROM headers too.

There a few good homebrew tools and libraries available. We did a gameboy game for a Ludum dare a short while back, and while it's certainly not pretty z80, the tooling got the job done. (Be gentle, it was my first time trying to do anything serious directly in assembly and we had a 72-hour time limit.) https://github.com/zeta0134/ludum-dare-42 We used the RGBDS assembler and its built in tools to make the thing, mostly because that runs on Linux and that's what we both wanted to develop on. My partner did the graphics and I got a decent flow going from LibreSprite using RGBGFX for the conversions. https://github.com/rednex/rgbds I'll admit that I did have a major advantage going in, having written a mostly functional gameboy emulator already, but emulating a system is very, very different from programming against its constraints. There a