Short, but sweet
The controls are extremely easy to pick up, and the gameplay itself is fast paced and fun (something missing from a lot of recent games). The graphics are as good as any other game on the Xbox.
The sound is what really makes the game. All of the voice acting (most of it by top notch actors like Lance Henriksen and Tom Skerritt) is exceptional. The music is perfect for the setting, and the ambient sounds are just right to make the game truly immersive.
There's one other thing that puts this game above the competition, at least in my view, and that's the cut scenes. There are just enough to keep the story moveing without makeing you feel like you're watching the game rather than playing it.