By Anthony Buchanan

Monsters vs. Aliens is the latest animated attempt to balance child/adult entertainment. It doesn't succeed: This movie is just for children (who definitely enjoy it). Lacking the intelligence of Wall-E and the boldness of Shrek, Monsters vs. Aliens falls after a strong beginning into overt carelessness, with the material and the clichés of the smart/deadpan cartoon. What made Shrek work? It had good writing, in addition to good animation and good humor. Shrek's humor could be enjoyed without being forced.

Monsters vs. Aliens never achieves the balance necessary to be enjoyed both by children and adults. Instead, it lapses into desperate gags out of the blue, and whatever fun there is to be had soon becomes stale.

The story starts with giddy girls who sneak into their friend's apartment to wake her up. Suzie, a dimly-disguised digital Reese Witherspoon, watches her suave newsman boyfriend propose to her on TV. Of course, she agrees. Then, guess what? The inevitable meteor crashes, and the wedding is…put on hold. Not yet teetering, the movie plays with a hammy feminist joke as the bride grows into a really big girl before being captured by the secret police. Smart kids will understand the clichés about marriage; adults will acknowledge them and then move on.

Sci-fi and plot abandonment take charge from here on out: We meet a general, who keeps all monsters and big girls hidden in a secret facility until the government calls on them as a last resort to fight off alien leaders.

Never mind exploration about rejection and the construct of "monster;" we've got nothing better to watch than the cliché and tired goofy characters: the dumb blue blob (Seth Rogen), whose every screwup is predictable; the freak scientist (Hugh Laurie), who has been done better 100 times; and the macho primordial reptile (Will Arnett), who would be better in a college delinquent movie. Such standbys are expected in this type of film, but that doesn't mean they shouldn't be done well. More action and an anticlimactic ending get mixed up in the desperate gags and out-of-place pop references, leaving the audience wondering where the writers are. By the time Steven Colbert's president starts to bust out rhymes to communicate with the confused aliens, I wasn't rolling in my seat; my eyes were rolling in my head.

But, in truth, the animation is what everyone cares about, and the animation in Monsters vs. Aliens is breathtaking, by far the only substance in this substance-free movie. Despite some pompous attempts to show off the newest 3-D technology—such as the bouncing rubber ball that seems like it's about to take viewers out of their seats—the effects overall are restrained and highly impressive. The best images are those of outer space with layer upon layer of matter that orbits the planets. The human world, alas, is a bit disappointing in contrast—for example, the Bay Bridge sequence looks just like a small model shot in reality. But failures like this are few. Let the kids have it; they'll know what to do.

Monsters vs. Aliens
Directed by Rob Letterman and Conrad Vernon
Written by Maya Forbes and Wallace Wolodarsky
With Reese Witherspoon, Seth Rogen, Hugh Laurie and Will Arnett

3-D: Regal Stadium 14
2-D: Dreamcatcher, Regal Stadium 14
94 min., PG