The family that eats together stays together, they say. But the proverb will have to be tweaked for director Caden Douglas’s cartoonishly grisly comedy, in which a family’s regular Sunday dinner ends with the neighbour’s dog running around the back garden with a severed human arm clamped between its teeth. You could describe Mother Father Sister Brother Frank as Fargo-esque, in the sense that it’s a tale of nice ordinary folks doing bad stuff while snow falls serenely around them – though in truth it is less flavoursome and the humour is more obvious, not so deliciously off-kilter.

It is lunchtime at the Jennings’ house, where mom Joy (Mindy Cohn) is a picture of homely friendliness. Her husband Jerry (Enrico Colantoni) seems a little grumpy while their grown up kids Jolene (Melanie Leishman) and Jim (Iain Stewart) bicker like teenagers, but that seems like fairly standard family dysfunction. Then in walks uncle Frank, a truly loathsome piece of work, sexist and nastily homophobic to Jim, who’s gay.

What follows is a frantic night of murder and family bonding. The script is not exactly light touch – and depends for a lot of its laughs on nice wholesome Joy swearing, or dad Jerry’s constant refrain of “They had a discount at Costco”. It ramps up with a knock at the door from a neighbour whose dog is missing. Then Jim’s husband – known in the family as “Shifty Pete” – shows up drunk, followed by a local cop. It’s entertaining enough; what’s missing, perhaps, is the spark of originality.

• Mother Father Sister Brother Frank is on digital platforms from 27 January.