Exceptional game and a bargain for the money
Controls are exceptional as well except for ONE flaw... the right control stick on a non-XBox360 or Playstation3 controller is locked into FPS-style with up=left, down=right, etc.
Very fun to play over and over again.... I have already beaten the game (on casual mode it's a little TOO easy) and am going through and unlocking the various upgrades in earlier levels.
This however is another knock on the game that lowers it from a 9.0 rating.... it doesn't remember after you beat the game that you have unlocked all the upgrades so that you don't have to unlock them AGAIN on your next run-through.