ibb and obb
ibb and obb is a game designed around cooperative play. Two players find themselves in a world split in two. In the bottom half gravity is reversed, enabling players to walk on both sides of the line seperating both halves. Portals allow the players to move from one side to the other. Puzzles and enemies are best dealt with through cooperation.
I ported ibb and obb from Playstation to Windows, Mac and Linux and integrated the Steam API to allow multiplayer games through Steam's peer-to-peer networking service.