The first sign of the apocalypse has come to pass. Microsoft has allowed Valve to release downloadable content for Portal 2 for free. That’s right, no hidden surcharge, no Microsoft Points involved.

Absolutely and totally free.

Download this now from the marketplace before the actual apocalypse happens and enjoy an additional multiplayer pack of challenges for Atlas and P-Body and new singleplayer modes.

EDIT: We’re aware that the content is also free on PlayStation 3 and PC, but it’s much rarer when Microsoft allows free content. :)