The two best things about the new action-comedy “Keeping Up with the Joneses” are that it follows many of the rules of conventional spy thrillers — from good guys and bad guys going up against each other to shrouding some of the characters in mystery — and that it never takes itself seriously. It really is a silly movie.

The premise is that a small street in a quiet suburban Atlanta neighborhood has a new couple moving in. Before that, Maple Circle was a place where everyone knew each other, most of them led happy but drab and predictable lives, and a highlight of the year was the annual block party. The story’s central folks are Jeff (Zach Galifianakis), an HR supervisor at a technology company, and a self-proclaimed “real people person,” and his wife Karen (Isla Fisher), a freelance interior designer. They’ve just dropped their kids off at summer camp, making them temporary empty nesters, and their lives could use some spicing up.

Enter those new neighbors, Tim and Natalie (Jon Hamm and Gal Gadot), a pair of what Hollywood would dub “beautiful people.” They’re good-looking, not bashful about public displays of affection, and they immediately become the centers of attention at that block party — him for his worldly storytelling, her for her … well, let’s just say she’s a stylish dresser.

But Karen, who needs to get out of the house more often, senses an air of mystery about them, and some behavior that first makes her suspicious of Natalie, then leads to her following her around town. Remember, though, that this is a comedy. Jeff, who Galifianakis plays as a kind of big, goofy puppy, and is into telling bad jokes or sharing awful puns, sees Tim as a prospective pal. There’s even some bonding when suave Tim brings square Jeff to his favorite secret restaurant, where the main dish is an extremely poisonous snake that’s killed at the table by a flamboyant chef, then cooked and served. Or was Jeff brought there and drunk so Tim can get information out of him? It’s up to the audience to decide whether the scene is there to slightly push the plot forward or to provide a good comic set piece. My opinion: It’s more funny than it is important to the story, and Galifianakis’ broad comic timing along with the pacing from director Greg Mottola (“Superbad,” “Paul”) push it to laugh-out-loud heights. And there are good comic contributions from Fisher, who shows off her slapstick side, and from Hamm and Gadot, who manage to be funny and mysterious and elegant at the same time.

Another nice touch is that when the comedy briefly takes a back seat to the mystery, and an action element is introduced, no holds are barred. Bits of who Tim and Natalie are and what they’re doing are revealed, and suddenly the screen is filled with guns, explosives, a high-speed car chase, talk of microchips, missile defense systems, and arms dealers, along with a terse warning from Tim that “things are not always what they seem.”

Fans of what Galifianakis has done in the “Hangover” films and on his excellent “Between Two Ferns” series (be sure to check out his President Obama interview) might be disappointed that, while he still does his antic bundle of nerves shtick here, it’s considerably toned down. But they should probably just accept it as something different from him. Truth is, he’s really good at it. The only bone to be picked in this enjoyable film is the inclusion of a tacked-on “one year later” ending. It would have been much better if it wrapped three minutes earlier.

— Ed Symkus covers movies for More Content Now.

“Keeping Up with the Joneses”
Written by Michael LeSieur; directed by Greg Mottola
With Zach Galifianakis, Isla Fisher, Jon Hamm, Gal Gadot
Rated PG-13