Marlon and Shawn Wayans' first stab at parody, 1996's scattershot 'hood-movie spoof Don't Be A Menace To South Central While Drinking Your Juice In The Hood, scored some big laughs, largely because it took on a juicy target that took itself very seriously. Scary Movie, in contrast, is a virtually scene-by-scene parody of Scream, a comic thriller that was itself a smart, satiric deconstruction of '80s slasher films. If Scary Movie's premise is fatally flawed, its execution is far worse, opening with a gag involving Carmen Electra passing gas and speeding downhill from there. One of the worst Airplane! descendents of all time, Scary Movie hurls countless terrible gags in a vicious assault on its audience's intelligence. Director Keenen Ivory Wayans keeps the film genuinely tasteless and taboo-shattering, but its jokes are so ineptly, hatefully executed that they almost evoke rosy nostalgia for the heyday of political correctness. Nowhere near as clever or subversive as its satirical target, Scary Movie is a proponent of the repetition-alone-is-funny school of filmmaking, which means running jokes about Shawn Wayans' homosexuality and a mentally impaired deputy that grow more grating each time they're repeated. But Scary Movie doesn't hit its nadir until its last half hour, when it resorts to an endless series of obvious, idiotic parodies of easy targets, climaxing in a Matrix parody that segues into a spoof of Riverdance. There are less pleasant ways to spend an hour and a half, but most have been outlawed by the Geneva Convention.