'emulate' is a relative word. You could say that pong was the first game to 'emulate' a tennis game. And some of the stuff like limping enemies has been done previously but likely have been pre-scripted

But seriously, although the gameplay doesn't keep the game entertaining, the rag-doll physics and destructable materials is pretty neat. I'm just a bit skeptical about how much of it is 'physics driven' and how much is just pre-scripted sprites or whatnot.

Also see the unreal engine tech demo at this year's E3 2008:
www.youtube.com/watch?v=-m4pe6UAS2M
(still just as skeptical though)

-NapkinG-