Valve has announced that Portal 2 will be expanding on October 4, with the new ‘Peer Review’ DLC, coming to PlayStation 3, Xbox 360, and PC.
Peer Review will include a brand new set of tests and challenges for players to solve in co-op, using Atlas and P-body; Portal 2’s co-operative robots built for testing. GlaDOS, the villain of the Portal series, will also be making a return with this new add-on — which is free.
In addition to the new co-op puzzles, Valve announced that Peer Review will also feature new single player content, in the form of a new Challenge Mode (available for co-op as well) that will come with its own new leaderboard.