downloaded the demo overnight last night (1.5 GB!) and played for about 10 minutes before work today. thought "bah, just another lame first person shooter." I had a couple pistols, I was shooting guys in a cemetery. big deal.
then when I got home tonight I gave it a second chance. after I got out of that cemetery? whoa, that game got weird. gory, sci-fi, excellent graphics, I'm going to have to pick this game up and see where it goes. It'll at least give me something to play until Assassin's Creed comes out.
It's not a very long game (I rented it from Hollywood Video about a month ago and beat it in a matter of about 10-12 hours), but it's a great game nonetheless. Excellent voice acting and moody visuals.
I suggest renting it and playing all the way through. It's especially fun when you get the "Darkness guns" from the crucified corpse in the pit of Hell (which manifests itself as a WW1 battle), and then bring said guns back into the real world.
Also, the game gets extremely fun once you develop the ability to create black holes to suck your enemies into.