The elaborate alternate reality game that served as a viral marketing device for Portal 2's release was not entirely devised by Valve. In fact, the developers of the 13 games of the "Potato Sack," the group of indie games central to the ARG's final resolution, say they were involved in the scheme's design from the…

Valve's vast potato-based conspiracy explodes today, as GLaDOS and Portal invade the thirteen games that were offered as part of Steam's indie game Potato Sack bundle. The horror!