Two quarrelsome pre-teen brothers (Josh Hutcherson and Jonah Bobo), left alone for the day, find an old sci-fi adventure board game in the basement; when they start to play, it turns into the real thing, with their house floating in the intergalactic void and beset by alien attackers. David Koepp and John Kamps’ screenplay is Jumanji in outer space (and based on a book by the same author, Chris Van Allsburg), and it slavishly follows the earlier film almost scene for scene. There isn’t quite the same emotional payoff, and the story, even on its own terms, doesn’t make much sense if you think about it. But director Jon Favreau keeps the adventure popping, and the alien “Zorgons” are genuinely terrifying—too much so, perhaps, for smaller kids. Dax Shepard is fun as a wandering astronaut rescued by the boys.