The most ingenious conceit of "The Secret Life of Pets" is right in its title. A warm, goofy computer-animated comedy delving into what happens when domesticated animals are left to their own devices while their owners are out of the house is ripe with possibilities. With the exception of the film's bookend segments, however, director Chris Renaud (2012's "The Lorax"), co-director Yarrow Cheney, and screenwriters Ken Daurio (2013's "Despicable Me 2"), Brian Lynch (2015's "Minions") and Cinco Paul (2011's "Hop") have opted for a standard part-caper/part-chase plot without the imaginative verve and quality of heart and humor that so often distinguishes Pixar and Disney features from their lesser competition. Arriving soon after two of 2016's best, "Zootopia" and "Finding Dory," Universal/Illumination's "The Secret Life of Pets" falters in comparison, too slight by a half and not nearly as compelling as one hopes.

Manhattan terrier Max (voiced by Louis C.K.) lives in contented bliss with loving human owner Katie (Ellie Kemper) until the day she surprises him by bringing home a second dog, the shaggy, ungainly Duke (Eric Stonestreet). Unwilling to share his domain with someone else, Max embarks on a scheme to frame Duke and get him booted as quickly as he arrives. When their growing contentions leave them lost in the city, hunted by both Animal Control Services and an underground community of feral animals led by vengeance-seeking rabbit Snowball (Kevin Hart), Max's friends—among them, adoring American Eskimo Gidget (Jenny Slate), nonchalant feline Chloe (Lake Bell), and wiener-dog Buddy (Hannibal Buress)—set out on a perilous journey to find them.

"The Secret Life of Pets" opens and closes beautifully, but everything in between plays like an afterthought, never as funny or heartfelt as it wants to be. The film certainly gets off to a promising start with a delightful montage of Max and Katie's tight-knit friendship in the Big Apple scored to Taylor Swift's "Welcome to New York," followed by observations—some exaggerated, some exceedingly true—of how pets entertain themselves through the day while their owners are at work. Likewise, the ending scenes set to Bill Withers' "Lovely Day" are so cozy and winning, returning to the selfless bond between humans and their animal children, one wishes the film hadn't just spun its wheels for over an hour in the middle. Alas, the core plot involving the lost Max and Duke's adventures and Gidget's mission to locate and rescue them simply isn't very interesting. The writing is mostly forgettable, with the inspiring voice work often swooping in to energize the proceedings; Louis C.K. (2013's "Blue Jasmine") is an unexpected but likable choice as Max, while Jenny Slate (also a standout in "Zootopia") is a pinball of exuberance as the forever fluffy Gidget, unable to disguise her love for Max any longer.

"The Secret Lives of Pets" is spotlessly animated, so colorful and picturesque it will make anyone want to book a trip to New York City post-haste. Indeed, the visuals are a great deal more appealing than the screenplay accompanying them. On Max and Duke's inevitable trek toward learning to co-exist and appreciate each other, the narrative grows repetitive, even tedious, with close-call chases galore and at least two run-ins with, and escapes from, Animal Control. An odd interlude at a sausage factory, complete with "Grease!" musical number "We Go Together," is positively ghoulish in where it leads. Above all, Universal Pictures and Illumination Entertainment are shameless in how tightly they have latched onto their most popular franchise "Despicable Me"—and, more specifically, the yellow comic-relief Minion characters—referencing both via sight gags and music cues (Pharrell Williams' "Happy"). Additionally, a prominent advertisement seen on the back of a bus for Illumination's next animated release, December 2016's "Sing," comes off as tacky. "The Secret Life of Pets" has its charms, to be sure, but could have only been improved with a creative retooling. Its central concept is so good it is a shame to watch as it falls by the wayside.