Paul Feig has a lot to answer for. Judd Apatow too, come to think of it. These two men, who cut their teeth on Freaks and Geeks, have cast the mould for modern American comedy: in Apatow’s case, extended tales about arrested adulthood, in Feig’s case, putting women front-and-centre of the kind of crude comedies dudes have been helming for decades. They’re both heavily reliant on improvisation, working off-the-cuff jokes into otherwise rigid narratives – to admittedly mixed results (all of their films, even the really good ones, suffer from clumsy editing and pacing from time-to-time).

On the whole, I feel pretty positively about each of these guys’ back catalogues. Yeah, sure, Apatow’s films are consistently a good 20 minutes too long, and Feig really needs a better sense of comic timing, but they mostly pull together enough funny casts and funny jokes to make for a good time at the movies. What I am a little concerned about is when their influence is carried over to weaker directors … like Jason Moore. After an auspicious debut – Pitch Perfect – he’s proved himself ill-suited to the Apatow/Feig brand of comedy with Sisters. Oh, it’s not terrible – a movie starring Tina Fey and Amy Poehler as sisters was never going to be terrible – but it’s just too uneven for the charisma of its stars to paper over its many flaws.

The story is simple enough. Maura (Poehler) and Kate (Fey) are forced into a hasty reunion when their parents (James Brolin and Dianne Wiest) sell off their family home. The sisters are devastated, naturally, since the house represents the childhood they can’t move on from (like pretty much every Apatow protagonist). Poehler is the responsible sister, with a stable career as a nurse but no kind of stable romance, while Fey is decidedly less responsible – she has a teenage daughter, but no job and no home. Left to their own devices in their parents’ house, they decide to throw one last party to relive their youth.

As a premise, it’s a pretty decent foundation for a comedy. And the first act is promising enough, as we’re introduced to much of the supporting cast – Ike Barinholtz playing against type as the object of Poehler’s affection, Maya Rudolph as an old school rival, John Leguizamo as a sleazy bottle story owner, Greta Lee as a nail salon employee – while Fey and Poehler trade witticisms and try on outfits. It’s lightweight, but fun enough. Regrettably, though, Moore chooses to stage the remainder of the film at said house party, and it’s at this point that the laughs start hitting diminishing returns.

The first problem is that we spend, like, a full hour at the party. That’s tiring enough if you’re actually at a party, let alone sitting sober watching a party full of forty-somethings get inexplicably raucous  (they quickly speed past a genuinely funny acknowledgement that people this age don’t tend to get especially ‘turnt’ or ‘lit’ or whatever the kids are calling it nowadays). The jokes are all standard issue – look, someone (Bobby Moynihan) inadvertently took hard drugs and they’re freaking out! – and a strong supporting cast is given little to do. John Cena, in particular, who proved his comedic chops in Apatow’s Trainwreck, is given little to do as a stony-faced drug dealer.

The big problem is that Paula Pell’s screenplay separates Fey and Poehler for most of the party, and tries to push against their already-established comic chemistry. All this effort has been expended to set Poehler up as the straight man to Fey’s more manic party animal, and then for the party proper, Fey has to play the “party mum” while Poehler endeavours to get messed up. There’s probably potential for that to be funny, I guess, but here it just sabotages what could’ve been a very funny dynamic.

There’s still a few laughs on the way to the expected ending; you will not be surprised to learn that the house gets wrecked and the sisters end up at each other’s throats before learning to move on with their lives etc etc. But a film starring Fey and Poehler – who have better comic chemistry than anybody, probably – should strive for more than “a few laughs.” At the end of the day, there simply aren’t enough jokes here to sustain the Feig/Apatow formula.