The first downloadable add-on for Portal 2, the free cooperative missions known as "Peer Review" is now out for PC, Mac, Xbox 360 and PlayStation 3 (or will be any minute now). And if you don't already own Portal 2...
Steam is selling Portal 2 at the very reasonable asking price of $14.99 USD for the next couple days. You have until October 6 to get that 50% deal, so if you're still procrastinating on one of the best games of the year, procrastinate no more.
Today's downloadable add-on for the game continues the co-op adventures of Aperture Science bots P-Body and Atlas in a new test track. "The DLC also features a single player and co-op Challenge Mode, and leaderboards to compare Challenge Mode scores with friends and the Portal community," says Valve.
Portal 2 [Steam]