I just finished the demo, and I've got to say:
Why the hell isn't it a standard nowadays for FPSs to show the player's feet?! Its so easy, yet it makes it look so much more realistic than looking down and a) not seeing a shadow and b) looking like you're hovering in mid air. Dont show feet, fine, but at least limit the user's view so that they cant look directly downwards to see their limbless bodies.
There was also a bit too much environment scripting. Right from the first level, as you walk, lights turn on, if you stop for a couple of minutes, no lights ahead of you turn on, yet the second you step close to the next light, no more darkness.
Other than that, it was pretty good.