Fans of the old “Rocky and Bullwinkle” cartoon show fondly remember its wisecracking sensibility and its refusal to take anything seriously, especially itself. And they remember its terrible puns, planted like time-release capsules in the brains of young baby-boomers, who would find themselves years later, sitting in some high school or college class, thinking “I get it! The college was named Wossamotta U!”

The best thing about this live-action update is that it is true to those qualities. It is so unpretentious that it is impossible to dislike.

Rocky and Bullwinkle, living in the animated world of Frostbite Falls since cancellation of their television show, are called back into action to defeat their long-time foes, Pottsylvanian spies Boris and Natasha (“Seinfeld’s” Jason Alexander and “Thomas Crown Affair’s” Rene Russo). The Pottsylvanian bad guys, including boss Fearless Leader (played by co-producer Robert DeNiro), have been brought into the real world and are plotting that perennial bad-guy favorite, total world domination, through television programs that turn everyone into zombies. Young FBI agent Karen Sympathy (Piper Perabo) seeks out her childhood heroes to help her save the world.

I think that in that paragraph I spent more time on the plot than the movie did. It’s really just an excuse for some gentle satire (“Ninety-nine percent of the country is slobbering in front of the television!” “What’s so strange about that?”), lots of jokes and guest appearances, and, of course, some really horrible puns. In fact, there are so many bad puns that some just get thrown away, as when the characters rush by a sign near a stream of water that says “Crimea River.” There are also lots of movie references. Robert DeNiro joshes his most famous line when Fearless Leader asks, “You talkin’ to me?” Jonathan Winters reprises his role from “It’s a Mad Mad Mad Mad World”, and there’s a “Hail Pottsylvania” song lifted from the Marx Brothers’ “Duck Soup.” So many stars show up for brief appearances that Whoopi Goldberg’s character is named “Judge Cameo.” Keenan and Kel, Billy Crystal, Randy Quaid, Janeane Garofolo, John Goodman, and a host of “that guy looks familiar” character actors pop up along the way. There’s even a tribute to Roger Ebert’s favorite movie cliché, the fruit cart in the chase scene.

Kids may miss a lot of the jokes that require a knowledge of old movies or the ability to recognize the guest stars or recognize Simon and Garfunkel’s “America” as Rocky and Bullwinkle drive off. But no one loves puns more than a seven-year-old (that’s why they spend so much time asking you riddles) and they will enjoy the interaction of the live and cartoon actors and the silly humor. Parents will enjoy seeing Rocky and Bullwinkle characters cope with the 21st century, as when Boris has to confront the dreaded “bad command or file name” error message and Bullwinkle discovers a new use for email. The actors all do their best to create an impression in what is really a cartoon environment, but Piper Perabo’s task is particularly thankless. Not only is her character Karen not very interesting, but she has to wear the most hideous clothes seen in a non-1970’s era movie in years, including a denim pantsuit that itself should have been enough to send everyone back to Frostbite Falls.

Parents should know that in order to market this movie to older kids by getting a PG rating, the producers have included brief mild language and cartoon-style violence. Very young children may be scared by the machine that turns people into vegetables (literally).

Families who see this movie should discuss Karen’s “ends justify the means” justification for stealing a truck and other dishonest acts, and Rocky’s reply, “But we’re supposed to be the heroes.” Older kids will enjoy the way that the characters are aware that they are in a movie — what people call “breaking down the fourth wall.” Characters talk back to the narrator. When Karen is asked to explain her behavior, she says, “I didn’t write this movie!”

Kids will also be intrigued by the way that Karen listens to the little girl inside her, and her conclusion that “what you believe in when you are young can still be true when you grow up.” That can lead to a good discussion of how many things change as you grow up, but some essentials remain a part of you forever.

Families who enjoy this movie should watch some of the original Adventures of Rocky & Bullwinkle cartoons, including the Fractured Fairy Tales and “Mr. Peabody and Sherman” episodes. They’ll also enjoy Jay Ward’s other creations, Dudley Do-Right and George of the Jungle.