In 2007, Valve wrapped up three of its newest and top FPS games into one package. Along with Half-Life 2, its first two episodes, and the multplayer classic Team Fortress 2, FPS fans also got Portal, which was a puzzle game in FPS form. Playing as a woman named Chell, and taunted by a computer AI named GLaDOS, it’s your job to test out the Apeture Science Handheld Portal Device. You move through a series of rooms, and you’ll have to make use of the portal gun to make it through each room and avoid tha hazards. Many of the rooms will involve a cube which you’ll have to make use of. It’s hard not to get attached to the cube. Even though it’s a short game, the darkly humorous story and crazy physics make it fun to play. Portal: Still Alive, an Xbox Live Arcade exclusive version of the game contains the original game and several new challenge rooms. There isn’t much of an incentive for anyone who already played through the original version, but at 1200 MS points ($15) this is perfect for those who have yet to play it.

Note: The standalone version of Portal is also available on PC for $20, as is the Xbox 360 version of the Orange Box.