[sneeuwpopsneeuw]

If anyone is interested in making a Gameboy game from scratch. Tonc is basically the resource that everyone is using to do that. https://www.coranac.com/tonc/text/

[propertymagnate]

I think that's only for the gameboy advance, although it is what most people are using for the GBA.

For the gameboy people use raw assembly or I think GBDK if using C, although I think there are some problems with GBDK.

https://github.com/gbdev/awesome-gbdev#c

[bbbbbr]

GBDK went mostly unmaintained for around ~20 years, and so it stagnated a bit. It has recently been upgraded to a modern version of the SDCC compiler with better optimization, and has seen bug fixes and a bunch of other improvements.

https://github.com/gbdk-2020/gbdk-2020