Here's what you tell yourself when you accept an assignment to review a cartoon about emoji: "Remember what you thought when you heard about The Lego Movie? That it was the most shameless bit of advertising-as-entertainment you could imagine, the nadir of Hollywood's intellectual-property dependence, and couldn't possibly be worth seeing? Remember how incredibly wrong you were?"

You were wrong then. Given the right combination of inspiration, intelligence and gifted artists, any dumb thing can be turned into an enjoyable film. But Tony Leondis' The Emoji Movie, a very, very dumb thing, comes nowhere near that magic combination. It is fast and colorful enough to attract young kids, but offers nearly nothing to their parents. If only this smartphone-centric dud, so happy to hawk real-world apps to its audience, could have done the same in its release strategy — coming out via Snapchat, where it would vanish shortly after arrival. But even that wouldn't be fast enough.

The project's first hurdle is imagining how an emoji icon, which by definition represents only one emotional state (or object), can be a character capable of experiencing a story. Its solution is incoherent. We're told both that "the pressure's always on" for the face-emoji residents of Textopolis to keep their expressions convincing — smiley or smirking, angry or puzzled — and that they have no choice: That weeping guy keeps gushing tears even when he wins the lottery; he's just programmed that way.

The exception is Gene (voiced by T.J. Miller), a youngster preparing to take over for his old man as the face of Meh. (Who could play the elder embodiment of Blah other than Steven Wright?) We learn that free-spirited Gene, thanks to some glitch, is capable of infinite facial expressions. He has a hard time being deadpan on cue.

His first time on the job, in fact, he fails. In the film's weirdly unconvincing vision of how emojis make their way from a phone's inner universe to its screen when the user selects them, the whole process breaks down if one of the actors can't sit still for a face scan. Gene wrecks the app's game show-like stage, and eventually, the program's supervisor (Smiler, a ruthless but always-smiling woman voiced by Maya Rudolph) targets him for deletion, sending a team of mean-looking antivirus bots off to get him.

With the help of a high-five icon (James Corden, taking his position as the story's fount of unrelenting enthusiasm very seriously), Gene sets out to find a hacker who can reprogram him and eliminate unwanted facial expressions. Jailbreak (Anna Faris) says they need to escape the phone entirely to do this, getting past a tricky firewall and out onto The Cloud.

Getting there affords the filmmakers plenty of opportunities for product placement. The characters spend several minutes stuck in Candy Crush (gags about Hi-5's sweet tooth go on about five times longer than they should); they nearly die in a Dance Dance Revolution-style challenge game. At best, these episodes are limp set pieces; at worst, they sound like they were written by ad agencies. When our heroes need to ride streams of music from one place to another, one coos, "Whoa — this is Spotify?!"; when Jailbreak leads Gene into Dropbox, their pursuers can't follow them inside because "this app is secure."

The dialogue is even lamer when the pic's three scribes depict the life of Alex, the high-school kid who owns the phone Gene inhabits. When Alex wonders what to text the girl he has a crush on, his pal scowls "words aren't cool" — in a Manhattan preview where critics were outnumbered by ordinary moviegoers, nearly all of the laughter was directed at this sort of line, where three grown men try and fail to convincingly imagine how kids talk. Hell, they can't even come up with fresh-smelling one-liners about the movie's resident poop icon. (Amusingly, the closing credits identify this slumming actor as "Sir Patrick Stewart.")

Leondis and company don't get much mileage out of the vast variety of emojis they might use for sight gags, but they do well enough with the slapstick adventure of Gene's quest from home to the cloud. If not always imaginative or digestible, the look of the settings and characters should keep kids awake for 86 minutes; and if the trick that eventually saves the day makes very little sense to critical moviegoers, at least it's cutely frantic eye candy. Even so, few adults in the theater will have a hard time maintaining the flatline, unimpressed expression Gene has such difficulty with.

Production company: Sony Pictures Animation
Distributor: Columbia
Cast: T.J. Miller, Anna Faris, James Corden, Patrick Stewart, Maya Rudolph, Steven Wright, Rob Riggle, Jennifer Coolidge, Jake T. Austin, Sofia Vergara, Christina Aguilera
Director: Tony Leondis
Screenwriters: Tony Leondis, Eric Siegel, Mike White
Producer: Michelle Raimo Kouyate
Executive producer: Ben Waisbren
Production designer: Carlos Zaragoza
Editor: William J. Caparella
Composer: Patrick Doyle
Casting director: Mary Hidalgo

Rated PG, 86 minutes