Combat is masterful. Easy to pick up and play, tough to master. Great stealth combat with gadgets and using your environment to to enemies down.
Lots of little collectibles to find which give you little back stories, art, character model viewers, etc.
Grand game. And if you get the dlc or the game of the year edition you get three different playable characters with their own challenges. --- if you don't know what Shadows of the Damned is. get on it. http://www.gametrailers.com/video/preview-shadows-of/714488