Graphics are pretty. Not a technological feat like Doom 3 was, but they are functional. Nothing here we haven't seen before.
Atmosphere; AA+++*++. It's like Soviet Union circa 1981 with aliens in the future! ( http://angryflower.com/only4d.gif
Physics are awesome. Period. Not sure if they are "better" that what we've been seeing in Doom 3, but so far they've certainly been put to much better use. (Albeit there are a few overly obvious setups.)
The facial expressions thing that people are gawking about is truly gawkable. Impressive stuff, looks totally convincing.
Gameplay is kinda ok-ish atm. So far I've just made it to the end (I think) of the canals section, so I've got quite a way to go yet. There are some great moments when you're running around and you're like OMG GUARDS, and you hop off into somewhere and like OMG MANHACKS and then you run into some exploding barrels and you like OMG EXPLODING OMG BARNACKLES! Excellent!
But inbetween those moments, sadly, it's walking along some place, oh hello guard, bang dead repeat.
Finally, Barney is fucking sexy ^_~