Easiest part to get started. Used in some commercial games (Grimace's Birthday grimacesbirthday.com ).
Built in graphics editor Built in music editor. But, it is visual scripting rather than C.
https://www.youtube.com/watch?v=BaxJz8UlHZY
Wonder: Use export graphics/music to use with other tools?
https://github.com/gbdev/awesome-gbdev
https://www.amazon.com/dp/B079X38DRS EverDrive GB X5
https://github.com/gbdk-2020/gbdk-2020/ GBDK: C compiler, assembler, linker and set of libraries
The C compiler is SDCC.
https://github.com/gbdk-2020/gbdk-2020/releases/latest/download/gbdk-linux64.tar.gz
https://mgba.io/ Emulator
https://github.com/gbdk-2020/GBTD_GBMB/releases/tag/2.4.5
http://chrisantonellis.github.io/gbtdg/ Graphics to C data converter.
Guides: https://www.youtube.com/playlist?list=PLeEj4c2zF7PaFv5MPYhNAkBGrkx4iPGJo
Engines:
http://zalods.blogspot.com/2017/01/zgb-little-engine-for-game-boy.html https://bitbucket.org/HellSuffering/retr0-gb/src/master/
Graphics elements:
Sprites Tiles Tile Map Scrolling Gamepad HUD