Alterego was a NES homebrew game by Shiru.
It's a quite fun puzzle game where you have to simultaneously control two characters and you have to collect the dots.
Collect all dots and you go to the next level.
Actually, it's a bit more complicated than that but you get the gist !
As for the development itself (end-users ignore) :
At first, i was trying to port alterego itself to SDL.
However, my unfamiliarity with bitbox caused me to drop this idea quickly.
I looked at bitbox's emulator and it's nothing more than a "simulator" compiled to native code.
Since the bitbox is just a framebuffer with a simple sound chip, it's pretty close to the real thing.
The only difference is that the "simulator" is much faster, since it's not running on the limited hardware :pDownloadOPK fileSource code