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.

Valve and recording artist The National announced the winners for their music video contest based on "Exile Vilify", a song penned by The National specifically for Portal 2.

The contest, which ran for over a month, tasked the community to make a music video for the song using whatever visuals they wished. Entries ranged from animated shorts, stop-motion, puppetry, and live-action. Over the duration of the contest, over three hundred entries were submitted.

Valve and The National, with the help of their respective communities, helped select two first-place winners in a virtual tie, both of whom will win a prize package. The winning entries, in addition to many honorable mentions, can be viewed at here.

On the PS3 Portal 2 will be supported by Steamworks, a complete suite of game features and services including auto updates, community features, downloadable content, and more.

The first title to support Steam on a console, Portal 2 offers cross-platform matchmaking, gameplay, friends, chat, and achievements, all powered by Steam. Steam on the PS3 also saves co-op game progress and single player saved games to the Steam Cloud, enabling players to pick up where they left off on any PS3.

The Steam overlay for PS3 provides access to both PSN and Steam friends, displaying their in-game or online status and providing a quick pathway to text chats, player profiles, friend requests, and game invites. Steam Achievements are earned in lockstep with PSN Trophies and are also accessible within the Steam overlay.

Steam on the PS3 provides access to all of these features once the player has linked their PlayStation Network account with a Steam account, which is done right within the game. A Steam user can login to an existing account, and anyone new to Steam can create an account with the click of a button.

In the spirit of Steam Play, linked players of the PS3 version of Portal 2 can also access and play their copy of Portal 2 on any PC or Mac by redeeming an in-box access code on their computer. The Steam client verifies the linked customer and then lists Portal 2 among their library of Steam games for PC and Mac.