It just lacks something.
That's probably what killed the game, the horrid HP system. Also, the monsters have a hella HP. It takes a while to kill one at times. If the recovery system was like the one in modern warfare 2, where you just find cover and avoid being hit, and you heal up, the game would be more fun.
The general feel to this game is very hollow and dark, the setting and graphics are very complete and nice. I think that's one of the good things about this game. It brings you to the setting.
To sum it up, there are slight flaws in the gameplay, it would have deserved a 8.5, if it was fixed.