There’s something undeniably intoxicating about subverting concepts and ideas imbued with the warm comfort of nostalgic purity just for the laughs. Seth Rogen’s Sausage Party transformed the idea of a cute, animated children’s movie into a just-for-adults gagfest. The Deadpool franchise has built its success on turning the established framework of the four-quadrant superhero movie into the raunchiest of R-rated comedies. When it does work, it breathes new life into aging ideas while often letting audiences look at the things they love through a different, sometimes more critical, lens. When it doesn’t work… it’s The Happytime Murders.

Directed by Brian Henson, son of late Muppets creator Jim Henson, the film is an attempt to give the cute and cuddly puppets that first shot to fame in the 1970s their own adult-centric makeover. It takes place in a world where puppets coexist with humans as second-class citizens, and the joke is that the puppets are grosser, depraved, and more lascivious than anyone could have guessed. Sure enough, the film gets things off to a fun and surprising start, delving into how a former children’s show puppet named Mr. Bumblypants has devolved into a helpless sex addict who scrounges around for porn and sex toys.

Then there’s the rest of the movie.

Phil Phillips (puppeted and voiced by Muppets stalwart Bill Barretta) is a disgraced former cop working as a private detective in Los Angeles. Phil embraces all the film noir tropes — the smoking, the cynicism, the reliance on voiceover. One day, he’s hired by a femme fatale puppet named Sandra White (Dorien Davies) who claims she’s being blackmailed. While tracking down a lead in her case, Phil ends up in the middle of a murder at an adult video store (run by puppets, of course).

Assigned to the case is Phil’s old partner, human detective Connie Edwards (Melissa McCarthy). The two had a falling-out years ago, which led to puppets being banned from the police force altogether. And while Connie isn’t interested in talking to Phil, much less helping him, they’re thrown together when it becomes clear that the adult store murder wasn’t a one-off. Somebody is picking off the puppet cast of a 1990’s children’s show called The Happytime Gang, and the duo has to get to the bottom of the mystery before it’s too late.

There are some fun, devious laughs in The Happytime Murders. Seeing Muppets recontextualized like this — particularly in their more extreme moments where they’re dropping F-bombs or having graphic puppet sex — holds the same kind of transgressive glee as, say, Team America: World Police. The film is rude and obnoxious to the point where it’s hard to believe somebody spent money making it. And whenever the audience is thinking exactly that, The Happytime Murders is at its best. But after the initial introduction, the outrageous moments come far too infrequently to sustain the glacial pace. (How glacial? The end credits of the film roll extremely slowly, perhaps half the speed as they do in other films, apparently in a bid to push the movie over a contractual 90-minute run time.)

From top to bottom, it seems as if The Happytime Murders hasn’t been entirely thought through. The movie toys with some commentary about racism and classism when first introducing the way the puppets are viewed in this world, but then, it ignores the idea entirely. The film goes with full gusto when it addresses the puppets’ carnal side — they love pornography and strip clubs, and almost all of them seem to be sex addicts — but it soft-pedals the drug front by giving them all a cute addiction to sugar. It’s a little baffling that a film with an explicit post-coital scene that involves copious amounts of silly string (seen in the trailer) still pulls its punches about narcotics. It makes even less sense when there’s an entire subplot devoted to Connie’s own addiction to sugar.

The Happytime Murders also falls short on good old-fashioned movie smarts. Like Team America before it, it’s essentially a satire. But instead of action movies, Henson and his team are sending up old noir movies and 1980s buddy-cop flicks. But the script, written by Todd Berger from a story by Berger and Dee Austin Robertson, doesn’t give the director or performers much to work with beyond gags and gimmicks. There are the expected topline clichés like that noir voiceover and Phil’s doting secretary (Maya Rudolph, who is easily the film’s best performance), which pay homage to hard-bitten detective films. Connie’s brusque attitude and sugar addiction attempt to push her in the direction of a Lethal Weapon-esque self-destructive cop. But the film’s satire is limited to those checklist attributes. Phil and Connie’s relationship plays out exactly as the audience would expect, and its banality is matched only by the tepid “mystery” that ostensibly drives the film — except for the inconvenient fact that the audience will likely guess the ending within the first 30 minutes.

That’s a common problem with projects that riff heavily on existing formulas in the name of satire. It’s one thing to lift plot elements and tropes to give audiences a familiar framework, but a movie ultimately needs to do the heavy lifting and build a competent, coherent story on its own. It’s as if the makers of The Happytime Murders saw the audacity of its puppets-acting-badly premise as a shortcut that would solve all things. Instead, the audience is ultimately left adrift. By the time the third act hits, it should be an exciting rallying cry, as the heroes try to finally stop the villain before it’s too late. Instead, it’s limp and lifeless, a ragged puppet with no puppeteer.

It’s frustrating that a movie that seems so improbable actually got made, only to fall so incredibly short. The actual Muppets are in the midst of a new resurgence; writer-actor Jason Segel helped reboot the franchise with 2011’s The Muppets, and Disney reportedly wants a new Muppets TV series for its upcoming streaming service. It’s the perfect time to playfully subvert the brand. Instead, The Happytime Murders squanders that opportunity. This is a film with the audacity to turn the color of a puppet’s pubic hair into a pivotal plot point. But that doesn’t matter, when a few years from now, nobody is likely to remember that this movie ever existed.