Here's good news for Wiibrew devs out there. Introducing Box2D for the Wii! Box2D is an engine primarily designed for emulating 2D physics. I was recently also used in the creation of WiiPhysics, a new physics playground program from Beardface. To use the program, copy the contents of libbox2d to your libogc/ folder. Make sure to read the documentation included in the archive.