Great story and atmousphere, cool combat mechanic.
Overall this is probably the best single-player game I have played this year and it was thoroughly enjoyable. The combat was memorable and introduced a refreshing change from the standard "head shot" mentality of most games. Dismembering a charging necro or shooting one of their explosive appendages and watching the ensuing mayhem is quite enjoyable.
The atmousphere is amazing, the lighting is one of the best parts of this game. There are several cases where the lighting tricks you into seeing something in your peripheral vision even though nothing is there, it really ads to the tension. The sound effects and voice acting are also top notch, which is saying a lot since many of the recent games have had terrible voice acting IMO. Play this game with the lights off to achieve the full effect and you will not be disappointed.
The story was top-notch and well thought out. I was thoroughly immersed throughout. My only complaint is that there was some repetition and backtracking, but that can be overlooked due to the fact that even retraced parts had been reskinned and detailed. The ending is obviously a cliffhanger since there will be a sequel, but many of the loose ends were tied up by the end so you don't feel disappointed.
Overall an amazing game, I would recommend this to any fans of shooters, survival horror, or just plain good story-telling.