A great puzzle/adventure game. I would love to see more levels, but for the money, there is plenty of fun.
Using the portal gun, you make your way past various obstacles. The setting is a research facility, where you are the lab rat, 'testing' the portal gun. Solving the puzzles was fun, and satisfying.
Graphics, and sound are as solid as anything from Valve. I run Vista on a Quad core with an 8500, and have had no issues with the game.
I can't recommend this game enough. The story is intriguing and ambiguous, and will keep you guessing, even after the end of the game. Essentially, you find yourself pitted against GLaDos, an A.I. that seems to have some of the same psychotic quirks as HAL. The ending is easily one of my all time favorites.
"We do what we must, because we can"