http://www.youtube.com/watch?v=x5_aHWEeyhE Footage from showdownLAN has surfaced on showing off a public playtest of Left 4 Dead, an ambitious zombie-centric team game from Turtle Rock Studios (Counter-Strike) and Valve. Four survivors take on waves of the Infected (think 28 Days Later) and four Super Infected as they make their way to a helicopter landing point. Shown in the clip is footage from four player-controlled survivors. Though the Super Infected can also be player-controlled, we don't have any video of that in action. There is, however, a moment where you can spot The Smoker strangling a survivor with its tongue. The video is grainy and shaky at times, but it's the best we've got on this so-far reclusive game. Left 4 Dead 411 has impressions from people who attended showdownLAN, as well as a gallery of the event. The game is due out this summer for PC and this winter for Xbox 360. Video embedded after the break.