While details in Valve’s official Portal 2 announcement were borderline nonexistent, retailer GameStop delivers the goods with a just-listed product description that drops word of “co-op multiplayer.” Apparently, the multiplayer component of Portal 2 will feature a campaign separate from that of the main scenario. This all-new mode promises “a unique story, test chambers, and two new player characters.”

Beyond the co-op mechanic, this multiplayer mode is set to bring significant change to Portal as we know it. According to the product listing, it’ll completely one’s perception of portals, requiring players to think outside the box cooperatively:

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.

Way to blow our minds, Valve. As for the single player portion, it is poised to “introduce a cast of dynamic new characters, a host of fresh puzzle elements, and a much larger set of devious test chambers.” With such a radical difference in gameplay and content between the two modes, it almost sounds as if we’ll be getting two games in one package. Nifty.

For what it’s worth, GameStop has pegged an October 26 release on the title. Not an official date by any stretch but does fall in line with Valve’s holiday release window.

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Read more: Portal 2 DLC Hitting Steam This Summer,  Valve: Free Portal 2 DLC ‘Peer Review’ Dropping October 4,  In-Game Editor Coming For Portal 2,  Perpetual Testing Initiative DLC Hits Steam May 8, Simplifies Portal 2 Puzzle Creation,  Portal 2 Summer Mapping Initiative Contest Announced