The smartest, funniest cheap monster movie import this side of June's Trollhunter, Attack the Block is a near-perfectly balanced seasonal trifle: Anchored in social realism yet determinedly goofy, it's neither too eager for laughs nor overtly preachy. Set in a sprawling London public-housing compound, the film follows a group of teenage hooligans as they stumble upon and eventually thwart an extraterrestrial invasion. Led by the angry but reasonable Moses (John Boyega), the kids defend their turf alongside fellow residents Sam (Jodie Whittaker), a nurse they half-assedly mug prior to the appearance of the ETs, and Ron and Brewlis (Nick Frost and Luke Treadaway), two underachievers who serve as a sort of stoned Greek chorus. Things move fast enough to distract from the movie's paltry budget — the woolly aliens, or "big gorilla-wolf motherfuckers" as Moses calls them, are plainly guys in suits — and give the film a Lord of the Flies by way of John Carpenter feel. (Joe Cornish, the actual director, is a well-known comic actor in Britain.) Attack the Block strains somewhat to deliver a climactic moral, but the way it slyly shifts our sympathies to Moses and his crew (at the expense of another species, granted) without overplaying their deprivation puts more serious-minded indies to shame.