If you’re going to build an animated film around a concept that’s dumb, flat, goofy, and obvious, and maybe a tad corrupt in its cartoon-to-toy-box opportunism, then you could probably do worse than the idea behind “The Emoji Movie.” On the one hand, it has the feeling of scraping — as in, we’ve had Trolls, Smurfs, and LEGO, now here come the funny-faced “expressive” ideograms on your smartphone. What’s next: “Automated Siri Voice When You’re Put On Hold: The Movie”?

Yet let’s come out and admit that the notion of a digitally animated feature that brings emojis to life does have its hokey-irresistible side. It goes right back to the feeling you had the first time you ever used an emoji — not ironically, but because you saw that it was tapping your inner child in a way that was kind of cool, especially when you realized that yes, you do have your favorites (personally, I lean on Sun With Face, Cowboy Hat Face, and Spaghetti). Any cynicism I might have had about “The Emoji Movie” was knocked away months ago by the film’s very funny trailer, which featured Steven Wright as the morosely indifferent, slightly constipated voice of Mel Meh. That trailer suggested that a seemingly obvious movie might be throwing you curveballs.

The bad news is that “The Emoji Movie” really is meh. There have been worse ideas, but in this case the execution isn’t good enough to bring the notion of an emoji movie to funky, surprising life.

The main character, it turns out, is the son of Mel Meh — a junior grouch-face named Gene (voiced by T.J. Miller), who is getting ready to make his debut in the bustling workplace of emojis. They all live in Textopolis, a city that’s embedded in the phone belonging to Alex (Jake T. Austin), a high-school freshman who keeps texting Addie (Tati Gabrielle), the girl he’s got a crush on. Each day, every emoji — Poop, Crying Face, Heart Eyes, Slice of Pizza — takes his or her place in a vast wall of cubes, which resembles a giant version of the tic-tac-toe board on “Hollywood Squares.” When one of them gets chosen for a text, his or her image is scanned, and all they have to do is sit there and be there adorable symbolic selves.

But Gene can’t do that. On his first day, he messes up, looking not so much like a Meh as like a Picasso who’s been in a bar fight. He gets branded a malfunction, and Smiler (Maya Rudolph), the corporate boss with a heart as cold as her grin is big, wants to see him literally deleted. Gene’s problem is that he isn’t a Meh. He’s got every face — every feeling — inside him. He’s like a Divergent who excels in every possible way, which in the one-emotion-per-icon world of Textopolis marks him as an unclassifiable noncomformist freak.

That sounds like a pretty good storyline, but the trouble with “The Emoji Movie” begins with Gene. He’s supposed to be a pinwheel of faces and emotions (you could almost imagine him as a digital version of the Genie in “Aladdin”), but as conceived by director Tony Leondis, and voiced by the comedian T.J. Miller (in an oddly unvaried performance), he’s the opposite of Meh — he should have been called Blandly Enthusiastic. The character isn’t an emoji chameleon, he’s a borderline bore, and he’s surrounded by johnny-one-note emojis who scarcely manage to eke out one good joke per identity. The notion of casting the elegant Patrick Stewart as Poop is funny on the surface, but his every line is another lame poop pun.

It’s obvious within 20 minutes that “The Emoji Movie” is going to be a knockoff of “Inside Out,” with the world of Alex’s phone as the film’s intricate and looming geographical “brain” (the apps are like candy-colored skyscrapers), and each emoji presented as a primal emotion. “Inside Out” showed that you could work comic miracles with characters like Anger or Sadness — not by varying them all that much, but simply by lending detail and passion (and great laugh lines) to who they were.

“The Emoji Movie,” though, is more than a bit lazy. It’s all on the surface, all movement and hectic situational overkill. Gene teams up with Hi-5 (James Corden), a once-popular emoji who’s been relegated to Alex’s back burner, and the two set off on one of those Generic Animated Journeys — in this case, to find the Cloud, where they think they’ll escape. They team up with a scruffy punk hacker named Jailbreak (Anna Faris), who’s really a Princess emoji running from her real self (another idea the movie does nothing with), and they navigate a series of apps, like Spotify, that begin to feel uncomfortably like product placement — mostly because the film never figures out anything fun to do with them. (Even the Twitter bird makes an appearance…but there’s no Twitter joke! Which makes you want to tweet your disappointment.)

It may sound like I’m being awfully hard on “The Emoji Movie,” since it’s friendly and “benign.” If you take young children, it will prove a perfectly okay pacifier. Yet the hook of the movie, to the extent that it has one, really is for adults. We’re the ones (and not just teenagers) who communicate, more and more, using these pop hieroglyphs, and the film should have made them into wildly popping characters — the kind you want to buy in a toy store not just because they’re cute but because they express something elemental. The emojis in “The Emoji Movie” said more before they opened their mouths.