For anyone who grew up with Maurice Sendak’s magical 1963 picture book, the idea of its slim story being pumped up into a live-action Hollywood feature must seem like a travesty. Director Spike Jonze (Adaptation) has translated it into a fairly beguiling screen experience, though by the end of its 101 minutes I was definitely ready for bed. To his credit, Jonze realizes Sendak’s beasts not through digital animation but through old-fashioned animatronic costumes fashioned by Jim Henson’s Creature Shop, and they lumber around with agreeable solidity (given voice by such actors as James Gandolfini, Catherine O’Hara, Chris Cooper, and Forest Whitaker). A realistic frame, in which the young hero (Max Records) rails against his neglectful sister and divorced mother (Catherine Keener), is warmly and gently handled, though the central story, detailing the personal politics between him and the six childlike monsters, steadily loses steam.