Portal is an excellecent game. Valve took an awesome concept and brought it to life, complete with interesting puzzles and great humor. My main problem with the game is the length. I feel it's way too short. But at the same time, I know that it wouldn't quite work as a longer game either, because I felt the puzzles to be easy. I never felt like I was at a loss of exactly what I was to do in every situation, even in the final level (which I applaud for taking the concept and forcing the player to apply it to new situations). The learning curve of the game in a sense programs the player (or at least it programmed me) so that it doesn't even have to fully analyze a puzzle to know what to do. I see a large drop in the floor, I can easily assume that I'm going to need to use gravity to propell me across some distance.
