[HELP] How to make ROM hacks like Metroid II DX

[Kran]

Hello, I'm working on modding/hacking ROMs and I was wondering how ROM hacks such as Metroid II DX are made. What I'm asking is, how do I add cgb/sgb enhancements to a ROM?

 

[Deleted User]

I can't be of any direct help, but have you tried looking at a game with a disassembly available that meets the criteria you're looking for? Pokemon Yellow may be a good place to start, as it plays on both GB and GBC as well as the SGB with a border. It'd be worthwhile to learn/understand how the hardware assigns color to sprites, where it gets that color from, and how the colors are stored. Something else that may be valuable would be to look at a game which has received a color remake, such as Link's Awakening and its counterpart, Link's Awakening DX.

 

[Kwyjor]

Hello, I'm working on modding/hacking ROMs and I was wondering how ROM hacks such as Metroid II DX are made. What I'm asking is, how do I add cgb/sgb enhancements to a ROM?

I understand it requires fairly deep knowledge of assembly language – you need to add color palettes to the ROM, and then add new code that loads that palette data. Writing and adding new code to any GB game is already very difficult.