It's 1984 and Michael Jackson's "Thriller" has conquered the world in writer-director Taika Waititi's loopy, charming coming-of-age story set in Maori New Zealand. Waititi (a former comedy mate of the Flight of the Conchords crew) also stars as a deluded, mostly harmless screwup dad, idolized by his scrappy young son (James Rolleston), who returns home after a short prison stint and wreaks gentle havoc. Boy could have been a twee mush of cuteness and bathos but it's not, in large part because of the outstanding cast of unself-conscious Maori kids. B+

