Portal is the definition of "Short, but sweet." Where I am trying out the advanced maps currently, this is one of those games you can easily load up and give a play whenever you need a quick game you can get through in a few sittings. The main objective took a good 2 hours to beat, the advanced puzzles and bonus maps might add on quite a lot of playtime. Highly recommend picking up this one if you haven't, as it's a really good time.