Horror-comedy Detention combines the bravura mash-up showmanship and Wikipedic ’90s pop-culture savvy of a Girl Talk album with the frivolous, non sequitur wit of Family Guy. Another way of saying the same thing: It’s one of the most obnoxious movies ever made. Dowdy student Riley (Shanley Caswell) is trying to figure out who’s responsible for hacking up the hipster student body at Grizzly Lake High School while dressed in the guise of the villain from the popular Cinderhella horror franchise. So far, so Scream—but Detention expands the frames-within-frames conceit of Wes Craven’s movies into a pop-culture hall of mirrors. Digressing into sci-fi time travel and Freaky Friday transmigration of souls before its prayed-for ending, Detention was lavishly self-financed and directed with sterile, kinetic razzle-dazzle by Joseph Kahn, whose long career in music videos has made his mind a flypaper of pop detritus, as reflected in one circling shot that seamlessly time travels through a student’s two decades in detention, with accompanying fashion and music cues. The biggest laugh is the overblown cinematography staging school lunch at red dusk, but “MMMBop” and “all that and a bag of chips” are what’s offered for punchlines. “It’s called post-irony,” says one character of the swarming references. I can think of another word for it.