This game was a lot of fun. You switch between dimensions to change the properties of the objects around you allowing you to make your way to the exit. The puzzles can often be solved in different ways, and for an added challenge there's a "par" for each level based on time and number of dimensional switches made. My biggest complaint is length. It was way too freaking short. DLC will be released for the game, though, and given the release price of $20 it seems reasonable enough. Best part of the game is that John DeLancie (Star Trek's "Q") is the acting GLaDOS.