"Aliens in the Attic" was originally titled "They Came from Upstairs" until the powers-that-be at 20th Century Fox decided that wasn't literal or generic enough. This contemptible way of thinking is also likely the reason why the film isn't better than it is. Truth be told, "Aliens in the Attic" would have delighted me as a child, but that was the 1980s, when CGI was rare and filmmakers like Joe Dante (1984's "Gremlins") and Richard Donner (1985's "The Goonies") used creativity and ingenuity while shooting their scripts and mounting their practical special effects. As a movie being released in 2009, this harmless but disposable action-comedy-fantasy amalgamation doesn't appear to be trying where it counts. Why bother, director John Schultz (2005's "The Honeymooners") figures, when computers can do all the work for you?

It's a mini-Pearson family reunion when parents Stuart (Kevin Nealon) and Nina (Gillian Vigman), along with teens Bethany (Ashley Tisdale) and Tom (Carter Jenkins) and adorable kid sister Hannah (Ashley Boettcher), vacation at their summer lake house in the sleepy Michigan town of Creek Landing. With Uncle Nathan (Andy Richter), Nana Rose (Doris Roberts), and cousins Jake (Austin Butler) and twins Art (Henri Young) and Lee (Regan Young) meeting them there, the plan is to relax and share some quality time together. That itinerary takes a raincheck when four small but decidedly unfriendly aliens land on their roof and sneak into the attic. Soon, all the kids are aware of what is going on, opting to keep the adults downstairs in the dark as they set out to defeat the invaders and save the world from doom.

"Aliens in the Attic" will prove to be entertainment junk food for children and merely tolerable for viewers in the double-digits. Director John Schultz and screenwriters Mark Burton (2005's "Madagascar") and Adam F. Goldberg (2009's "Fanboys") have made a nutrition-free but agreeably paced lark that winds down after an unfussy 86 minutes. The premise of aliens attacking a home, even in a family movie, has no excuse to not be the least bit threatening. The creature designs of the pint-sized fiends—three antagonists and one helpful child alien who befriends Hannah a 'la "E.T.: The Extra-Terrestrial"—are supremely unoriginal and bland, and the CGI effects that bring them to life are underwhelming to match. There is simply nothing special about them outside of their seemingly natural ability to speak in English.

More fun is the mayhem the aliens pull on the humans, like sucking away the gravity in a room, turning Bethany's obnoxious boyfriend Ricky (Robert Hoffman) into a remote-controlled robot, and transforming Nana Rose into a kung-fu-fighting zombie whose false teeth remain on Jake's arm after she pulls away from biting him. There is also a very funny gag involving a rotary phone and the contemporary children's outright confusion over using it when they decide to call the police. Intermittent moments of wit like this are appreciable, but attempts at dramatic conflict, like Tom's admittance that he has been purposefully doing badly in school as a means of hiding his intelligence and becoming more popular, are hokey in the extreme. Meanwhile, the climax wherein a laser with the ability to increase the size of the aliens is uncovered buried beneath the house's basement is over and done with in a timely manner even if it doesn't exactly raise one's pulse level.

"Aliens in the Attic" will keep a certain segment of the audience absorbed—not that they will learn much from it. The morals are slim, with the teamwork between the siblings and cousins shining through the brightest, but otherwise what you see is what you get. Ashley Tisdale, of "High School Musical" and "The Suite Life of Zack and Cody" fame, is perhaps the biggest draw in the cast, looking alternately cute, frustrated and understanding as college-bound Bethany. The other kids do professional work, too, and Doris Roberts (2006's "Grandma's Boy") delights in getting a big stunt-laden fight scene at the age of almost eighty. "Aliens in the Attic" is inoffensively mediocre, bereft of subtext and depth but too playful to get terribly bent out of shape about its shortcomings. It could have been a whole lot better, but it also could have been a great deal worse.