This passable entertainment feels like a movie a kid might discover on TV on a rainy day. Based on a 2003 fantasy novel by Jeanne DuPrau and directed by Gil Kenan, City of Ember takes place in the future but is anachronistic to a fault. Ember, an underground city home to the world’s only remaining (and nearly all white) humans, is strewn with old pipes, wires, and light bulbs. When the generator that powers Ember begins to fail, it’s two young teens, Lina (Saoirse Ronan) and Doon (Harry Treadaway), who realize how high the stakes are. Kids who see the truth when adults cannot is a — if not the — central idea in children’s stories, but today’s kids would hardly recognize the grown-ups in Ember’s totalitarian society. Bill Murray plays (for laughs) the city’s corrupt leader, but it’s jarring casting that only reminds you how outdated the film is. Tim Robbins chips in as Doon’s crackpot-inventor dad. 95 minutes | Boston Common + Fenway + Fresh Pond + Chestnut Hill + Suburbs