The best part of this game is slow motion
This might be one of the most FEARful experiences you have in a PC FPS. That alone, however, isn't enough to make this game "great".
There is nothing wrong with this game, it works perfect, very fluid when played on a decent rig. My biggest problem with the game is with the ending -- that and the fact that it plays a little too easy.
This game is a bit of a snack. It'll get your heart pumping, but in the end, you'll be wishing for more substance. Good graphics, good sound, good gameplay, you won't go wrong here. But... Don't believe the hype. This is just another FPS, and it's pretty short.