How to Be Single is a film about four women – Dakota Johnson, Rebel Wilson, Leslie Mann and Alison Brie – searching for meaning in New York inside and outside of romantic relationships. The film is similarly in search of an identity, swerving from low-key indie dramedy to broad romantic comedy from scene-to-scene with reckless abandon. The film’s diverse approach isn’t always successful – it’s neither as funny nor as poignant as it thinks it is – but its charming enough to sustain its runtime, offering up some gentle resistance to romantic comedy conventions along the way.

Abby Kohn, Marc Silverstein and Dana Fox’s screenplay neatly lining up its characters along the rom-com continuum. Johnson’s character, Alice – the closest we come to having a protagonist – could have easily slotted into a Noah Baumbach or Baumbach-esque film (alongside, say, How to Be Single co-star Alison Brie in Save the Date). Having recently suspended a four-year relationship (with Nicholas Braun), she experiments with both casual flings (with Anders Holm) and serious relationships (with Damon Wayans Jr.) on a circuitous path to self-realisation.

Playing Alice’s sister, Meg, Leslie Mann imbues a similarly realistic type – a long-single ob-gyn doctor deciding to becoming a mum – with her trademark screwball energy, shifting us closer to the manic rom-com familiar to audiences. Brie’s character, Lucy, sits somewhere in the middle; on the page, she’s a total caricature, flourishing wedding magazines at would-be suitors and melting down in front of kindergarten students. But Brie – usually a reliable performer – leans on a brittle anxiousness that’s ill-suited to the character; it’s perhaps not a big surprise that she ends up being pretty superfluous to the narrative in the final cut. And then there’s Wilson, doing her thing; I find her ‘outrageous’ overacting and litany of ‘hilarious’ one-liners pretty insufferable, but your mileage may vary (if you liked her in Pitch Perfect, you’ll like her here (because she’s the same character)).

The first half of the film promises something akin to Friends with Benefits or, more recently, Trainwreck – a rom-com that stacks its deck with lots of (gasp) casual sex before flipping over a full house of committed, heteronormative relationships. Despite the title, you don’t really expect that any of these characters will finish the film actually single. Though Christian Rein’s cinematography resolutely resists the genre’s conventions, offering up handheld camerawork, soft lighting and the occasional bit of creative photography that more closely resembles a title from a French Film Festival than a commercial comedy.

This proves to be more than just a cosmetic choice on the part of director Christian Ditter. While How to Be Single might fervently flirt with contemporary rom-com conventions, populating its first act with a litany of meet-cutes and comic misunderstandings, it’s a little bit more sophisticated than the product of screenwriters discovering that – shock, horror – people have sex outside of committed relationships (looking at you, No Strings Attached). Instead, the film evolves into a more nuanced depiction of modern romance; nothing too profound, but driven by an understanding that ‘true love’ isn’t as simplistic as these films tend to make it out to be. (Though the total absence of Tinder – or a plausible analogue – keeps it from feeling too contemporary.)

How to Be Single turns out to be the rare rom-com whose final act is better than everything that preceded it; but that’s not to say that it’s not without its own problems. It’s overstuffed, for starters: as mentioned, Brie’s character is largely sidelined (she exchanges literally zero lines of dialogue with the other three actresses billed on the poster), and Wayans Jr’s (surprisingly touching) arc feels undercooked, relying on the strength of its actor rather than any substance in the screenplay. It feels as though a tighter script is sagging under the pressures of accommodating the right line-up of stars to attracts audiences; I can’t imagine the first draft would’ve been so unwieldy.

For instance, this overreach forces Mann’s path – towards pregnancy and beyond – into some awkward shortcuts. If this were, indeed, a straightforward rom-com, then I’d be more forgiving of the conceit that a resolutely-single professional woman – who’s delivered 3,000 babies, as we’re told on more than one occasion – impulsively decides to impregnate herself with donated sperm after a brief encounter with an (admittedly, very cute) bub. Her subsequent reluctance to commit to the ever-charming Jake Lacy is just as unbelievable; we’re given too little time with either character to buy her hesitancy or his persistence.

The screenplay’s ‘subversion’ of genre tropes – more of a gentle ribbing than a wholehearted deconstruction – isn’t sophisticated enough to offer an explanation or excuse. Nor is the film funny enough to get away with such chasms in characterisation. The big comic setpieces fall flat: Brie’s pyjama-clad encounter with old school friends is a particularly cringeworthy attempt to generate laughs. Only the quieter cuts of banter connect with the funny bone. Maybe there’s a sliver of intentionality there – a demonstration that broad comedy is more embarrassing than hilarious when it’s happening to you – but it’s a thin excuse throughout a flabby midsection.

Still, the final minutes – and Johnson’s gentle, charming performance – provide enough perspective on the genre’s pitfalls to forgive the moments where it topples over into the same pits. It’s nice that How to Be Single chafes against its compatriots’ insistence on ‘happily ever afters’ predicated on conventional couplings, but it’s a shame that it couldn’t offer more insights – or more laughs – along the way.