Super Mario Clouds is an old Mario Brothers cartridge which I modified to erase everything but the clouds. This project was very much in the line of the stuff various BEIGE (aka Beige aka Beige Programming Ensemble, etc, etc) representatives Paul, Joe, Joe were doing then. Anyway, check below for the ROM, source code, a gif, a scan of the cartridge, a video, and instructions on how 2 make it yourself. (via Super Mario Clouds)