The Slamdance Guerilla Games Competition, as it's fully called, was a part of the Slamdance Film Festival, which fucked itself over when it denied Super Columbine Massacre RPG! entry, followed by Braid, Everyday Shooter and many others dropping out because of this decision, practically destroying the event's name.
Sam Roberts was in charge of the Guerilla Games Competiton, which was started in 2006, where in the same year N won the Audience Award for Best Game. The next year, the Slamdance festival director decided to pull Super Columbine Massacre RPG! from the contest on claims of it being too offensive. This decision was in turn offensive to a lot of the other entrants, the makers of Toblo, Everyday Shooter, Castle Crashers, Braid, FlOw, Once Upon A Time and Book And Volume. This pretty much obliterated any legitimacy the event had, leaving very few finalists in the run, and killed the event.
After this fiasco, Sam Roberts started IndieCade, along with Stephanie Barish and Celia Pearce, first as part of E3, later as an independent event in Los Angeles. with lots of supporters like Robin Hunicke, Will Wright, Kellee Santiago, Eric Zimmerman and Keita Takahashi.