Portal

If you're looking for a unique puzzle game with a twisted sense of humor, Portal is a good bet. Released for the PC in October 2007, Portal features a series of levels filled with obstacles, moving platforms, and shooting turrets. In the spirit of first-person shooters, you get a gun. However, it's not your typical gun--instead of bullets, it shoots portals.

Here's how it works: Let's say there's a deep chasm separating you from the exit. You can use your gun (Aperture Science Handheld Portal Device) to open up an exit portal on the other side of the chasm, and an entrance portal on your side. Go through the entrance portal, and viola, you're on the other side of the chasm.

Of course, that's only the simplest scenario you'll encounter. The levels become devilishly more complex, forcing you to think in new ways as you try to escape from a level filled with obstacles and robots that try to kill you. Your only companion is a female robotic voice that "guides" you through the levels. "The voice" gives much of the game its personality and humor, teasing you and cracking jokes in the most deadpan manner.

At first the game is presented as simply a series of tests for your character, an Asian woman named Chell. The computerized voice promises that Chell will receive cake if she reaches the end of the test. However, all is not what it appears to be.

The biggest problem with this game is that it is far too short. Many people can beat this game in a few hours. But it's fun, unique, and well worth playing.