The people who made Aliens in the Attic probably will not be surprised to hear that their film is mediocre, given that they don't seem to have been shooting for anything better than that anyway. I picture the walls of the production office lined with motivational posters that say "Good Enough!" and "Why Waste Effort?" And when they're all done, and the C+ grades come out, everyone shouts "Woo-hoo!" and trades high-fives.

Titled They Came from Upstairs until just a couple months ago, Aliens in the Attic is a family-friendly version of an alien-invasion B-movie, with most of its cast culled from the sweatshops of Disney Channel and Nickelodeon programs. The primary setting is a spacious lakeside rental home in Michigan, where teenage math nerd Tom Pearson (Carter Jenkins) has unwillingly come to spend the Fourth of July with his immediate family, three cousins, an uncle, and a grandma. Making matters worse, his sister, Bethany (Ashley Tisdale), has schemed to let her weaselly boyfriend, Ricky (Robert Hoffman), stay there, too. And then, making matters even worse, aliens crash in the attic.

There are four of them, vaguely reptilian, all computer-generated, about knee-high. Their aim is to destroy humanity, though this is offset by their being bumbling and argumentative, lest they frighten the kiddies in the audience. Their neatest trick is that they can shoot a little dart into your neck and then remote-control you to do their bidding. But it only works on adults, leaving Tom and the other kids as the only hope to save the world.

What ensues can best be described as "cute." Tom's war-obsessed cousin Jake (Austin Butler) is thrilled to be fighting a real battle. Jake's little brothers, a set of twins (Henri Young and Regan Young), put their video game skills to use when they steal the remote control that the aliens are using on Grandma (Doris Roberts). Tom's baby sister, Hannah (Ashley Boettcher), befriends the youngest alien, a timid fellow named Sparks (voiced by Josh Peck), and thus becomes the single most important person with regard to the salvation of mankind.

The screenplay, by Mark Burton (Madagascar) and Adam F. Goldberg (Fanboys), adequately brings an alien invasion down to a kid's level. The aliens deploy an anti-gravity device that causes the kids to float around the room, which is pretty neat, and at every turn the children outsmart their parents, who generally fail to notice that anything other than standard horseplay is going on upstairs. (Kevin Nealon and Andy Richter are wasted as a dad and uncle.) A few references to grown-up sci-fi movies are thrown in, too, as when the twins demand of the aliens, "What's your weakness? Water? Earth germs?" The English-fumbling aliens (with J.K. Simmons, Kari Wahlgren, and Thomas Haden Church among their voices) made me chuckle here and there, and I have to admit I smiled at the goofiness of Tom's final heroic declaration to the invaders: "You messed with the wrong mathlete."

Small pleasures aside, though, the movie (directed by John Schultz, who made Like Mike and The Honeymooners) doesn't offer anything particularly memorable or inventive, and too much of its "comedy" relies on Ricky, the boyfriend, getting possessed by the aliens and behaving crazily. This would be a perfect role for an actor who has a gift for slapstick; Robert Hoffman is not that actor. The more he mugs and grins and falls down, the more grating the character is. I'm not saying he ruins the movie, but he certainly doesn't help it.