Making homebrew for the Nintendo DS was how I got into programming in the first place. Devkitpro was too confusing for me back then, so I used something called PALib, essentially a pretty hacky library built on top to make it "easy".

Nice community at the time though, I made a pong clone where the main selling point was that you could switch between different "themes", and a bunch of people contributed some really nice custom ones to be included.