Great, Scary, prefer the original.
Gameplay: Just like any other shooter, point, shoot, hope you don't get killed. I've seen it before, and much prefer Half-Life 2.
Graphics: Yes, these are good. I've seen better, but they're good enough to give you a good scare. My only problem is that it makes everybody in the game look completely ugly.
Sound: A bunch of groaning from monsters. That's about all you'll hear. Sure, they talk every once in a while, but mostly you will hear groaning.
Value: Sure, you may play through it a couple times, but you'll find it boring after a while.
Overall: I think that you should play the original over this, not only is it better, it's free. There are plug-in's that allow you to play the original, I would recomend getting that to have a good experience with this game. If you want a good shooter, go to Half-Life 2 instead, it's a much better game.