Anomaly 2 is a sequel to the critically acclaimed Anomaly Warzone Earth. Maintaining the core elements of the original, Anomaly 2 adds plenty of new features: unit morphing, over million tactical combinations, post-apo world and tower defense vs tower offense multiplayer mode.
I am not sure didn't want this key code and came with a bundle. From what I read and what Humble Bundle says that you don't need anything to this game.