NDS homebrew: https://www.youtube.com/watch?v=FO9llfJbHZ8
The game can run on the real hardware or using a DS emulator.
I'm putting on GitHub source codes of my old homebrew games. I should have done that years ago. At that time I was learning a lot about games development, therefore the source code quality is far from perfect (and the comments are in French!).
I would like to clean up the code a bit and someday port them to the 3DS.