Portal 2

"Portal was a test bed. Portal 2 is a game."

- Doug Lombardi

Portal 2 is the sequel to Portal. First hinted in the updates made to Portal in March 2010, it was announced on March 5, 2010 to be released in Fall 2010.

Portal 2 was previewed in the twelve page cover story of the April 2010 issue of Game Informer, revealing some plot details and new gameplay features. It has also been confirmed that GLaDOS is indeed still alive, and is slated to return as the main antagonist. In addition, Game Informer and other sources have also confirmed a co-op mode for up to two players with its own separate campaign.

Confirmed characters

 * Chell
 * Two unnamed robots
 * GLaDOS
 * Wheatley

Confirmed enemies

 * Aperture Science Sentry Gun

Development
In 2007, Kim Swift stated that future Portal developments would depend on the community's reactions, saying, "We're still playing it by ear at this point, figuring out if we want to do multi-player next, or Portal 2, or release map packs." On January 31, 2008, Lombardi confirmed that "more Portal" would be forthcoming, and promised that the additional content would not just be "more puzzles"; an interview with Kim Swift on February 21, 2008 revealed that a full sequel, Portal 2, would be coming. Swift also stated that the team creating the Portal sequel were deciding upon the design they should implement and that a multiplayer Portal "from a technology standpoint is possible", though Swift had previously stated they tried a Portal multiplayer variant, but admitted that "it's less fun than you'd think."

On June 10, 2008, Kotaku reported that Valve was seeking voice actors for the character role of Aperture Science CEO Cave Johnson and suggested that the second game may be a prequel to the Portal events. However, it was later suggested on Kombo.com it could be a sequel, with Johnson as another AI.