Just downloaded the 'free' game. However it seems to be playing really slow. Simple things like scrolling around the mouse cause graphics skips. I seem to get like 2 frames per second. The FAQ says it should work with graphics cards made in the last 5 years.
My computer is under 2 years old. It's an HP with dual core AMD 4800+ x2 processor and "GeForce 6150SE nForce 430 graphics". The system came with some pretty powerful 3D games that play just fine. However, this game does not. :(