If you don't think games have the power to scare you, I dare you to play this one
The atmosphere, the atmosphere, the atmosphere, baby. I have never been as literally frightened by a computer game as I was by this one. Beyond that, the monster AI is quite good, in a they-really-just-make-a-beeline-for-you kind of way, and of course the graphics and (particularly) the sound are stellar, as one would expect from Looking Glass Studios. Much has been made about the fact that this game uses Thief's Dark Engine, but let me tell you that that all comes to nothing in the end. Making everything photo-realistic wouldn't have added a thing to this game. It's as completely immersive as anything you'll ever play.
The story is slightly hackneyed (think Alien with only one person investigating the distress beacon this time--you), and I found some of the dialog on the recorded messages you discover lying around the ship a bit hard to swallow, although the voice acting is competent enough. Also, the weapons wear out far too quickly and there is not nearly enough ammunition to get through some areas unless you already know what to expect and conserve accordingly. Monster respawning takes place far too frequently--sometimes right in front of your face--as well, although that can be adjusted with a patch.
The Bottom Line
Worth its weight in gold to any fan of the Alien movies, RPG's, and/or shooters. Worth a look from everyone else if for no other reason than to see what is probably the greatest character ever invented for a computer game, Shodan.