Taken from: http://kotaku.com/5486758/portal-2-adds-multiplayer-co+op-new–familiar-characters
Officially released details on Valve’s sequel to Portal were scant. Fortunately, retailer GameStop comes through with some major details, including the addition of a two-player cooperative campaign mode and all-new characters.
Gametops’s description of the PC and Xbox 360 game indicates that Portal 2 is due later this year—the online retailer lists an October 26 release date—bringing with a cast of “dynamic new characters” and “never-before-seen areas of the Aperture Science Labs.” And yes, as hinted at earlier, players will be reunited with GLaDOS.
The only details on Portal 2’s multiplayer mode from GameStop are that it will feature its own unique story-driven campaign. The “new mode forces players to reconsider everything they thought they knew about portals,” requiring players “to not just act cooperatively, but to think cooperatively.”
Here’s the full product description.
Coming this holiday. Portal 2 is the sequel to 2007’s Game of the Year and draws from the award-winning formula of innovative game play, story, and music that earned the original over 70 industry accolades. Features single and multiplayer co-op modes. The single-player portion of Portal 2 introduces a cast of dynamic new characters, a host of fresh puzzle elements, and a much larger set of devious test chambers. Players will explore never-before-seen areas of the Aperture Science Labs and be reunited with GLaDOS, the occasionally murderous computer companion who guided them through the original game. 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.