Dwayne “The Rock” Johnson is a great movie star in search of a great movie.

Since his breakout work in the WWF, Hollywood has struggled to find a home for the impossibly charismatic beefcake. While not suited to the grim and gritty likes of Walking Tall and Doom, an unlikely role in Be Cool – the charming if forgettable sequel to Get Shorty – revealed his true potential. Playing a gay bodyguard with a heart for show business, his tough guy aspirations tend to be overshadowed by his showbiz ambitions – as in a memorable scene where he pivots from swinging a baseball bat at John Travolta to delivering a monologue (or ‘dialogue’, really) from Bring It On.

That scene is Johnson’s career in microcosm – violence preceding chafing against heteromasculinity, a torrent of goofball charm and, finally, a brusque attempt to push him back into more conventional gender roles. (“You might think about doing a part written for a man,” advises Travolta with an air of condescension.) Johnson is typically the best thing about the movies he’s in, but few of those films – whether quality stuff like Fast Five or middling chaff like Hercules – really let him flex his comedic muscles.

Central Intelligence promises to be a corrective to all that. An action-comedy whose trailers play up the ‘comedy’, it pairs up Johnson with 2010s-favourite-comedian Kevin Hart (facilitating the kinda-clever-the-first-time tagline, “Saving the world takes a little Hart & a big Johnson,”) and gives the former plenty of opportunities to demonstrate his knack for silly comedy. Playing a CIA agent, Johnson exhibits puppy-dog enthusiasm along with a fondness for unicorns and bum-bags (a reference to this still-hilarious photo); Hart’s relegated to the role of straight man as an accountant roped into a search for some kind of world-threatening MacGuffin. Nuclear codes, maybe? I dunno. It doesn’t matter.

Or it shouldn’t, anyway. Central Intelligence’s biggest mistake is forgetting that no-one goes to see movies like this for the intricacy of the espionage plot, spending far too much screentime on the particulars of its half-baked twists and turns. In particular, it decides to commit to developing the possibility that Johnson’s character, Bob Stone, is in fact a psychopathic bad guy. It’s a baffling decision, partly because there’s no way the audience believes for a second that he’ll actually turn out to be the villain, but mostly because it interrupts – and sometimes straight-up sabotages – the intended comedic chemistry between Johnson and Hart.

When that chemistry is firing – as when their characters, who attended the same high school, reunite at a bar after a surprise Facebook friend request – it’s killer, helped along by the occasional great line (exhibit 1: “You look like a black Will Smith!” exhibit 2: “You were a power couple, like Taylor Swift and whoever she’s dating right now!”). It’s a time-honoured dynamic – enthusiasm meets reluctance – but the plot machinations keep getting in the way. It doesn’t help that Hart keeps trying to be Eddie Murphy when he’s supposed to be playing Judge Reinhold, either.

Perhaps Hart’s reluctance to slot into the straight man archetype can be forgiven by his character’s backstory – or, really, the shared backstory of Johnson and Hart’s characters. When they were at school, “Bob Stone” was Robbie Weirdict, a fat outcast bullied and belittled by his peers; the film opens on a flashback to him being tossed onto the basketball court in front of the entirety of the school, buck naked. (Why, precisely, he was showering why the rest of the school were at assembly is never satisfactorily explained.) Hart, meanwhile, was Calvin “Golden Jet” Joyner, the most popular and successful kid on campus. His anxieties that he peaked in high school arguably contribute to his increasing discomfort playing second fiddle to Bob, along with his increasing reluctance to play nice, particularly when faced with CIA heavies like Agent Harris (Amy Ryan), with whom he exchanges otherwise out of character banter.

Central Intelligence might have been that great film that Dwayne Johnson deserves had it spent more time developing the aftereffects of this shared backstory rather than spending so much time on spy shenanigans. Director Rawson Marshall Thurber’s take on the men’s shared insecurities is often pretty broad; case in point, they cast Jason Bateman as the grown-up bully who tormented Robbie, which is about the most obvious casting choice in the world (especially if you’ve seen The Gift).

But broad is necessarily bad in this kind of comedic context, and when most of the film’s best moments revolve around the two men coming to terms with growing up into someone they never thought they’d be (along two entirely different trajectories, granted) it’s hard not to wish they’d pushed this angle harder than the “Jason Bourne in jorts” stuff. Especially when the film’s climax occurs at the pair’s 20 year high school reunion, a scene that should play as triumphant and cathartic but instead feels sorta rushed. There is a great cameo, mind you.

Maybe the emphasis on espionage/action could have worked had there been any weight to this plot, or political substance or, hell, an entertaining action scene or two (one imagines the budget may have been a restrictive factor here). Instead, Central Intelligence feels sadly typical of Johnson’s filmography – miles from terrible, but another missed opportunity to harness the fundamental force of The Rock.