I have always liked emulation and wanted to make a ROM, when I was younger I wanted to do it for the NES because that was all my device could emulate, but chose the GBA since mobile devices are fast enough to emulate it(I was using a Palm z22 when I wanted to make a NES rom) and it is the only one with C++ support and a framebuffer.(NES and SNES are usually done in assembly)
There are a few demo versions but it is nowhere near complete.
What does not:
Levels Have Not Been Made