Back in the era of Saturday matinées, “Aliens in the Attic” would have been just fine sandwiched between a couple of cartoons and a newsreel, especially if about half an hour was lopped off and there was a bit more imagination or wit in the title invaders. It’s probably better suited for DVD and a pizza at slumber parties than for an $8 movie theater ticket. But as long as no one expects too much, this is not a bad time-waster.

The Pearson family: mom, dad (SNL and “Weeds” vet Kevin Nealon), love-struck teen queen Bethany (“HSMs” Ashley Tisdale), sulky middle child Tom (Carter Jenkins), cute sock-monkey-clutching kid Hannah (Ashley Boettcher) are joined in their vacation home by their grandmother (Doris Roberts of “Everybody Loves Raymond”), uncle (Andy Richter), and cousins, aggressive Jake (Austin Robert Butler of “Zooey 101″) and gamer twins (Henri and Regan Young). Tom is not happy with himself, with being away from his computer, with having to go fishing, with any of his family, and especially with the uninvited arrival of Bethany’s boyfriend Ricky (Robert Hoffman), who seems able to fool everyone but Tom with his good manners and preppy appearance. And then there are the aliens in the attic, four little green creatures with many arms who have come in search of something they need to take over the planet. One of their most potent weapons is a mind-enslaving dart that turns humans into remote-controlled zombie slaves.

But it only works on adults.

And so the kids have to learn how to work together to protect the grown-ups and the planet. What works best in the film are the special effects, clearly the primary focus as the talented cast, including Tisdale and SNL vet Tim Meadows, get less attention than the CGI and wire work. The gamer expert twins use the Wii-style remote to manipulate the zombified Ricky and grandma, the kids have to assemble weapons with whatever they have on hand, and the aliens turn off the gravity and get tangled in a Slinky. A lot of slapstick and a little crude humor went a long way with the kids in the audience and there were frequent hoots of delighted laughter. I could hear some of the punchlines repeated and stored for later use. (That last point is as much a warning as an endorsement.)