12 8 2009-05-15T12:15:52-04:00 This is a graph of Left4Dead player engagement over time. Each day GamerDNA tracks game play through Xbox Live, Steam and Xfire. Here we have graphed that daily activity, comparing PC Left4Dead player engagement to Xbox 360 Left4Dead player engagement. 137286 0 143646 Left4Dead.jpg 399662 716 image/jpeg 959 2009-10-09T13:52:10-04:00 0 true true 2009-10-09T13:52:10-04:00 8274 3625