Matthew Lillard's directorial debut, "Fat Kid Rules the World," is a standard coming-of-age movie; it never does anything surprising or adventurous. But if you accept it on those terms, it's an entirely serviceable ode to punk rock as the ultimate panacea for teen angst. Based on K.L. Going's young-adult novel about an overweight teen who discovers his much-needed catharsis by banging on a drum set, "Fat Kid" occasionally suffers from the feeble conventions of an afterschool special, although it rises above those trappings largely thanks to an impressive turn by Jacob Wysocki. Proving his emotionally resonant work in "Terri" was no one-trick wonder, Wysocki credibly embodies depressed Seattle teen Troy, a hopeless recluse still reeling from the death of his mother and struggling to get along with his cold-blooded father, a police officer whose job influences his stern parenting skills.