Today's most vertigo-inducing video: Portal Lvl. 13 Time Challenge

All we can say is, don't stand too close to the edge while watching this video. You'll slowly lose your equilibrium and tip over, falling into the void without a Portal gun to save your ass. In fact, we just watched it a second time, but made sure that our seatbelts were securely fastened, and that our tray tables were in the full upright and locked positions. We survived, and have now ordered a cocktail and another packet of peanuts with which we can calm our jittery nerves.

Portal continues to stick out of every corner of The Orange Box as one of the coolest, and shortest, titles we've ever played. We'd love to see some new levels made available on a regular basis, as well as some FPS that will let us use the Portal gun on unsuspecting foes. Bring it on.