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.

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.

Marking the debut of Steam functioning on any next generation console, the features shipping in the PS3 version of Portal 2 include cross platform play (PC/Mac vs. PS3) for multiplayer games, persistent cloud-based storage of PS3 saved games, and cross platform chat (PC/Mac and PS3).

Valve announced that outlets worldwide (retailers and Steam) are now accepting pre-order reservations for Portal 2.

Special pre-order offers vary at participating outlets around the world and include a variety of dollars off and/or exclusive in-game content for those who reserve the game for purchase before it is released the week of April 18. These include $5 off the full price, exclusive in-game skins for the coop bots (Atlas and P-body), and more. Check your favorite outlet for details.

"Portal 2 is shaping up to be the most innovative title in Valve's history, and to be a much larger experience than we originally planned," said Doug Lombardi, vice president of marketing at Valve. "As such, we are aggressively promoting the title with more retail promotions than we have put behind any prior release."

PC System Requirements

• OS: Windows 7 / Vista / XP / 2000
• Processor: 3.0 GHz P4, Dual Core 2.0 (or higher) or AMD64X2 (or higher)
• Memory: 1GB XP / 2GB Vista
• Hard Disk Space: At least 7.6 GB of Space
• Video: Video card must be 128 MB or more and should be a DirectX 9-compatible with support for Pixel Shader 2.0b (ATI Radeon X800 or higher / NVIDIA GeForce 7600 or higher / Intel HD Graphics 2000 or higher).
• Audio: DirectX 9.0c compatible