A while ago I downloaded the demo for Clive Barker's Undying, a very well designed game. It is based on one of the 3D engines, I forget which one right now, but it is very easy to get used to and the game play is very fast. I can really appreciate the speed of my video card with this game, which gives quick smooth movement most of the time. I don't know how far throught the demo I've gotten, but it seems to be a pretty well thoughtout game, only with occasionally difficult monsters to destroy.