This game is incredible, with a deep storyline that will interest kids and keep adults hooked. You don't need to play the original Portal to understand it (although many players recommend it), and the humor is A-plus. It will stump even the best of players, who will need to use logic and basic physics to get through the game. Parents with younger or more sensitive kids should do their homework first, though: there is a remark about how, "You [the player character] ARE adopted, and that's terrible," some jokes about the player character's weight, and a man (who is never seen, but is heard on recorded messages) who is dying of a poisoning caused by moon rocks. Digging deeper into the game files will turn up some more disturbing unused lines. So definitely be wary of the game, but know it contains a great mental workout and storyline.