The first half of this 80-minute roadside diner siege horror plays out almost like a section of an anthology film, calling to mind the nasty little slasher The Gas Station in John Carpenter and Tobe Hooper’s Body Bags project. The opening 40 minutes or so mostly sticks with the same location, and the focus is initially on one character: newly pregnant waitress Nancy (Jessica Belkin), whose dad (Jeremy Sisto) owns a modest diner in the middle of nowhere, and who has put her in charge of that evening’s imminent night shift. It’s not exactly the world’s most enviable nepo baby gig, even if you’re not attempting to suppress mounting waves of nausea, and so Nancy is cranky and in no mood to take any flak from either a gang of punks on dirt bikes or the surly “legacy hire” chef Jake (Taylor Kowalski), whom she summarily fires after he mouths off.

This is a mistake. Left to work the night shift alone, she quickly realises how vulnerable she is when masked hoodlums show up. In most siege movies, it would be time to buckle up and see if the director has the chops to keep the tension going for the rest of the runtime. Last Straw has other plans, however, with a nifty perspective switch that breaks the film in two. To say more would spoil the story, but it’s a neat idea. The downside is that having invested in Nancy by this point, the audience has to reframe what’s important here.

Still, it’s encouraging to see low-budget early-career film-making with ambition. Perhaps that shouldn’t be a surprise from director Alan Scott Neal – he may be making his feature debut here but he has been working in casting on original and innovative film and television for a while now, including Euphoria, the Safdie brothers’ films and Nathan Fielder’s The Rehearsal. It wouldn’t be surprising to see further interesting work from him building on the promise shown here.

• Last Straw is on digital platforms from 23 September.