I played it not so long ago. Its "okay". Its your standard FPS with a kind of focus on Melee attacks. You can string together combo's and use the environment to finish people off.
Its a little freaky and slightly scary.
Personally I think I wouldnt have missed out on much had I not played it. The one thing that is cool is teh whole evidence gather element of the game. You had a PDA with a few functions, such as an ultra violet light, that you use to gather evidence through observation and logic. That was pretty cool! But there is not much of that, not enough to make the game somehting that everyone should play.
I played dead space. Not bad. But im sorry, its really not freaky enough for me. Condemned has this awesome way of FULLY immersing one into the game. Look, I only recently got Xbox, so im totally used to playing games on my computer, but i have to say I've personally never enjoyed a game this much.