An unwieldy mix of elements from Star Wars, Tron and boot-camp movies, Gavin Hood's adaptation of Orson Scott Card's novel is heavy-going.
Asa Butterfield is the adolescent hero, plucked from his family by Harrison Ford's martinet military commander to go to battle school so he can learn to save the world from locust-like aliens. (Kids, we are told, are better than adults at assimilating the data you need to wage war by computer.)
There is an eccentric performance from Ben Kingsley as a tattoo-covered military guru. The battle scenes are spectacular but lifeless and hard to engage with. We're watching a cascade of computer-game imagery.