Well, Valve couldn’t call it the “Summer DLC” if it’s coming out in October. Portal 2 fans both single player and co-op rejoice, as both campaigns get a little extra in this update. A new challenge mode will be added for both campaign modes with leaderboard support, and a new co-operative test track will be added to put P-Body and Atlas through another gauntlet of brain strain. “Peer Review”, as it’s called, will debut across all release platforms on October 4th, for free. And yes, GLaDOS is featured.
Valve also released the third and last soundtrack compilation from Portal 2, which can be downloaded here.