Worth playing, it isn't perfect, few games with such long developement times are but its a fun shooter with a twist.
This game had been in development for a LONG time, it was originally slated to be a xbox title but got changed to a 360 game part way through developement. That being said I was impressed with the graphics, usually games that began life on another gen-console don't look this good (see STALKER). There are some control issues especially when controlling the Darkness powers but none that are game-crippling.
My biggest complaint is the save system. I find it inexcusable today for games to use checkpoint systems. The 360 has a hard drive so why can't we save anywhere? Now days EVERY game should allow you to save your progress at anytime. The checkpoint system here isn't as bad as the save system in Dead Rising (one of my favorite games but that save system sucks) but it can still be annoying to have to re-play segments every time you die. If you are a FPS fan looking for something with a bit of a twist then the Darkness powers should fit the bill. They could have been made a bit more useful, sometimes it is harder to use the powers than to just shoot everything but it is more satisfying when you use your demon powers to slay a foe.
The game does a great job of immersing you in the storyline though the side trips to the otherworld (a hellish WW I) seem kind of out of place as if they came from a different game.
Its not as good as Chronicles of Riddick but not too many games are, I recommend this title.