This Game Is A Phenomonal Puzzle on "good graphics" steroids!
Let's first just mention that this game is very short. I beat it in about 4 hours of intense mindbending playing.
Basically, this game is a puzzle-like sex child straight from the laboratories of Valve.
You play as a labrat named Chell, who is given an Aperture Science portal gun very early on, and must advance through many test chambers that will challenge you everytime. Each one becomes more difficult than the last. All the while, you are walked through the test chambers by a mysterious AI, named Glados, who uses cake as a way to motivate you to complete each Aperture Science test. The game's mechanics feel very similar to Half Life 2, even the portal gun is similar to the Gravity gun, probably because in the lore, Black Mesa and Aperture were rivals. As you're playing, you can't help but admire the atmosphere, even if it is mostly white walls. If your in to only open world games, then you will hate this. You will probably go stir crazy, shit, and die. Overall, this is a phenomonal game, and i recommend picking it up in the Orange Box, so you can recieve the Half Life 2 parts, Team Fortress 2, and best of all, Portal.