I played it a while ago, with a friend of mine on his LAN. We had a lot of fun with it in co-op.
It's pretty fiddly when it comes to procedures, but that's part of the game's challenge; you're a SWAT officer that's going in to subdue suspects, not a soldier clearing an apartment block in Fallujah. Sometimes it can play like that, but sometimes the mission(s) require you to arrest rather than blast into atoms.
There's one level that's particularly creepy, where you're going in to rescue someone from a serial killer. The environment is highly creepy.
I'm considering buying it, but I don't have much time for it.