It’s a Wonderful Knife review – seasonal classic refitted as comedy slasher horror

Here is a classic example of a film you root for, fervently willing it to be brilliant. It’s got Joel McHale from Community in it – great. It’s got Justin Long committing to a bit as a Trump-style property baron with blond hair and spray tan – fabulous. Even more exciting: there’s a role for Katharine Isabelle, star of beloved turn-of-the-century horror comedy Ginger Snaps, as a cool lesbian aunt.

The premise is fun, too: a loose remake of It’s a Wonderful Life as a comedy-horror about a teenage girl called Winnie Carruthers (Jane Widdop), whose life goes to hell after she kills a masked maniac. This leads her to wish she had never been born – a wish then somehow granted by the cosmos. In turn, this gives said masked maniac a free hand to establish a reign of terror over the little town of Angel Falls.

But sometimes you can have all the right ingredients and the recipe doesn’t quite pan out as you’d hoped. It’s a Wonderful Knife is diverting enough to start with, as the plot clicks efficiently into motion with the requisite stabbings and impalings. Unfortunately, there’s not enough fuel in the engine – the characters don’t have quite enough to do, we can’t care quite enough about them, and the world-building is nearly-but-not-quite convincing.

Some of the comedy-horror tropes employed here call to mind the likes of Buffy the Vampire Slayer – which in fact did something similar in the episode The Wish, which imagined the titular slayer never came to the vampire-ridden town of Sunnydale. But TV enjoys an advantage over film in at least one respect: the runtime of a single episode, on average, doesn’t need as much sustenance as a feature film, and what works very well at 40 minutes just feels stretched out at 90.

• It’s a Wonderful Knife is released on 1 December on Shudder.