Tired of being mugged by high-school thugs in a Manhattan that’s notably scummier than the real thing, the teen hero of Kick-Ass wonders, in a hilariously put-on and intermittent Brit’s New Yawk accent, “How come nobaddy’s eva tried to become a suppahero?” Dave (Aaron Johnson) soon learns the hard way that trying to intimidate thieves while wearing a ridiculous green wetsuit/superhero getup elicits first laughter and then a beat-down. But as soon as he’s back on his feet—this time with damaged nerve endings and steel bone reinforcements—he’s back on the street. His bumbling attempt to battle a four-man crew attracts a cell-phone, cam-wielding crowd—which in turn scares off the bad guys. “Who are you?!?” asks an amateur videographer. Ready for his close-up, Dave sneers, “I’m Kick-Ass!” With that phrase and Dave’s heroic antics catapulted into the memespace, Kick-Ass is real. In its first half, Matthew Vaughn’s Kick-Ass offers a fairly astute, if light, assessment of how new media has provided fresh outlets for the age-old instincts of heroism and hero worship. Dave seems to be in the crime-fighting game less to save lives than for the MySpace glory. But no hero (and no would-be franchise kick-starter) gets off that easy, and thus Kick-Ass launches into its second hour, a mess of random source cues and progressively brutal action setpieces. Kick-Ass devolves into a show reel for its own ancillary characters; expect to see a lot of slutty Hit Girls toting mock bazookas this Halloween.