Portal 2's Aperture testing duo P-Body and Atlas are back on October 4th in a chunk of DLC titled 'Peer Review'. The best part? It's completely free! The add-on will download automatically via Steam on PC and Mac, and will be available on PSN and XBLA starting Tuesday.
Alongside the new co-op testing track, which will see you run into GLaDOS once again, the DLC will offer both singleplayer and co-op Challenge Modes along with Leaderboards.
Get testing on Tuesday!