This is great stuff. When I was working on a platformer I'd read a lot of the code for these classic games (Mario, Metroid, Sonic, Megaman, etc.) to see how they did platforming and what the character physics tuning numbers looked like. I've been meaning to do a series of articles that break down games, focusing mostly on gameplay code, enemy behavior and physics. The only comprehensive article I've found like this is the Pacman dossier (http://home.comcast.net/~jpittman2/pacman/pacmandossier.html). Everything else is random bits and pieces that can be pieced together, but would be nice to have in one place.