Portal 2 is a hilariously mind-bending adventure that challenges you to use wits over weaponry in a funhouse of diabolical science.

Using a highly experimental portal device, you'll once again face off against a lethally inventive, power-mad A.I. named GLaDOS. And this time you won't be alone. Meet an expanded cast of characters as you think your way through dangerous, never-before-seen areas of Aperture Laboratories.

Break the laws of spatial physics in ways you never thought possible, with a wider variety of portal puzzles and an expansive story that spans a single player and co-operative game mode.

The game's two-player cooperative mode features its own entirely separate campaign with a unique story, test chambers, and two new player characters. This new mode forces players to reconsider everything they thought they knew about portals. Success will require them to not just act cooperatively, but to think cooperatively.

The "Perpetual Testing Initiative" allows players to easily create, share, and play Portal 2 puzzles. The Initiative comes with a simplified puzzle maker that allows that creation of mind-bending puzzles without ever leaving the game.

The puzzle maker can directly publish maps to the Steam Workshop where users can browse, vote on, and select to play them. Selected puzzles will automatically be downloaded and installed inside Portal 2.

Portal 2 Perpetual Testing Initiative DLC will be available for the PC/Mac on May 8th.