“Night at the Museum: Battle of the Smithsonian” is a cute, kid-friendly, wacky comedy, with monkeys. And if there is one thing we can count on in this world, it is that monkeys are funny. Take it from the entertainment professionals who made this film.

At one point Ben Stiller (as night watchman Larry Daley) and two feisty capuchins do a Three Stooges face-slapping routine that runs, as I recall, about 35 minutes. One monkey slaps Larry. The other monkey slaps Larry. Larry slaps both monkeys. Which is pretty funny. But not nearly as funny as when they do it again. And again. And again and again and again and again. The first “Night at the Museum” has Stiller in a slap-fight with a single monkey, so this is definitely twice as funny. If you’re 9.

The jokes and puns on display here are older than the mastodons in the diorama, but does that really matter? Kids will love it, just as they love lukewarm pizza, stale cola and soggy French fries.

Adults drawn to the film by its superlative cast — Ricky Gervais, Christopher Guest, Hank Azaria and Steve Coogan, to name a few — will find it disappointingly light in the laughs department. You watch it wondering why the studio didn’t release the outtakes theatrically and make the film a bonus feature on the DVD.

The sequel to the big family hit “Night at the Museum” struggles with a big creative challenge. The sense of wonderment you feel seeing museum displays magically come to life is not as strong the second time around. If you’ve seen one playful T-rex skeleton, you’ve seen them all.

Larry isn’t surprised by the displays’ nocturnal antics anymore; how could we be? The solution offered here is to move the action from New York’s Museum of Natural History to the Smithsonian, the world’s largest collection of art and antiquities. More displays, more artifacts to bring to life.

This approach introduces Guest as Ivan the Terrible, Azaria as a nasty pharaoh and Amy Adams as spunky flier Amelia Earhart, but makes the film too busy, with too many characters and too much going on. It’s action-packed, colorful and visually diverting but not that much fun.

If a fraction of the ingenuity that went into the computer graphics had been directed toward the script, the film could have been a delight. Instead, the story is the captive of the effects. Al Capone and a couple of hoods show up, not because they have anything compelling to contribute to contribute, but because the technicians figured out a way to render them in black and white alongside characters in color.

There are moments amid the special effects excess, to be sure. Azaria’s lisping Egyptian is a silly tribute to Boris Karloff, the movies’ original Mummy. Azaria throws himself into the peevish role with such gusto that his commitment becomes a joke in itself.

If you have children to baby-sit, you could do worse, but the people who made the film could have done much better.