The teen hero of Kick-Ass is tired of being mugged by high school thugs in a New York City that's notably scummier than the real thing and wonders, in a hilariously put-on 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 get-up 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!" In its first half, Matthew Vaughn's Kick-Ass offers a fairly astute, if light, assessment of how new media have given fresh outlets for the age-old instincts of both heroism and hero worship. Dave seems to be in the crime-fighting game less to save lives and more for the MySpace glory. But no hero gets off that easy, and thus Kick-Ass launches into its second hour, which is a mess of random source cues and progressively brutal action set pieces. 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.