Zathura understands kids’ inclinations to transform dens into forts, view a cocked thumb and forefinger as a laser gun or attempt to make the biggest explosion sound ever with their mouths.

Imagination got trumped by Industrial (as in Light and Magic) for the effects-heavy Jumanji, a film to which Zathura is a quasi-sequel only because they share a plot (an adventure board game comes to life, this time in outer space) and source author (Chris Van Allsburg).

Zathura is reminiscent of 1980s movies that had effects, yes, but not at creativity’s expense. Creature creator Stan Winston does great work here, and check out the brief shot of the smaller, internal robot piloting its brawny shell.

By further comparison with Jumanji, this five-character film is a chamber piece, and is far better for it. This game only affects those it needs to, and director Jon Favreau (Elf) knows that the bad-guy aliens don’t need to run amok down the street to inject tension into his story.

Despite the best creature-stalking sequence since maybe Jurassic Park, even the tension comes more from bickering brothers with age-based differences than any interstellar dangers.

Ten-year-old Walter (Josh Hutcherson) is more interested in sports highlights and his unseen “girlfriend” than playing with his 6-year-old brother Danny (Jonah Bobo), who can’t understand why Walter “got so mean.”

No one would like to think kids this age, least of all their kids, swear mildly at each other. But chances are, they do. Screenwriters David Koepp and John Kamps recognize this without pushing the boundaries of the PG rating (it’s just the “B” word and a “D” word rhyming with “sick”).

The two brothers have a teenage sister, Lisa, who sleeps the day away (Kristen Stewart) and a divorced, ad-executive Dad. Tim Robbins makes the most of a bookend role that doesn’t even bother to provide a name.

Naturally, Walter and Danny ruin one of his projects; in the scene, Bobo has the rushed “I’m sorry, I’m sorry, I’m sorry” down cold. Dad leaves the kids at home alone to run into work and make another copy. That’s when Danny finds Zathura in the basement, the house becomes a suburban-style spaceship and the brothers must work together to get back home.

The game’s attention to rules (specifically turn-taking and cheating) is both a challenge to Danny and Walter and a source for several laugh-out-loud bits. When Lisa is cryogenically frozen on one turn, Walter’s first instinct is to melt her with a lighter and aerosol hairspray. She becomes a fine sliding joke.

Then there’s the stranded Astronaut, who becomes a great asset to Walter and Danny, but also needs their expertise. MTV personalities attempting to act rarely succeed (ahem, Johnny Knoxville) but Punk’d lackey Dax Shepard is heroic, helpful and humorous in a role offering a great twist. (Pay attention to the “time sphincter” line. It’s more than just a funny body part in the script.)

Zathura‘s excitement comes from wowing sights of a living-room meteor shower, a renegade robot in need of re-programming and meat-eating, planet-burning lizard aliens called Zorgons.

But the adventure’s appeal comes from knowing that kids could act out Zathura‘s astronaut with a jetpack by strapping on a backpack and letting their boundary-free imaginations rip away. It’s one of the best live-action family films of the year.