If you’ve ever tried to make a home movie with young children, you quickly come to appreciate how hard it is to get the little monsters to remember their lines and hit their marks, let alone give good performances. It’s an education in the difference between good and bad direction, the raw, primary-teacher skill in herding cats while also managing tone, quality control and all that storytelling stuff. Just try it for yourself and you’ll realise just how good a job directors such as Garth Jennings or Taika Waititi did with child-led films like Son of Rambow or Hunt for the Wilderpeople.

At the very least, this awareness will help you be a bit more forgiving of a film like Riddle of Fire. This would-be work of whimsy stars three kids – eldest but still preteen leader Alice (Phoebe Ferro) and her friends Hazel (Charlie Stover) and Jodie (Skyler Peters), the last two brothers – who are spending their leisure time in remote Ribbon, Montana, knocking about and getting into trouble, like kids do. Except that writer-director Weston Razooli lays on a faux-medievalist vibe, with ye olde-style subtitles and a pseudo-fairytale structure that turns their adventures over a day or two into a kind of quest, like something out of the Brothers Grimm or JRR Tolkien. In order to get the password the boys’ mom has used to lock the TV, preventing them from using the games console they just stole, the kids must find or make a blueberry pie for her. The need for eggs gets them mixed up with a gang of rednecks who poach wild animals to turn into taxidermy creations, led by Lio Tipton’s evil witch-like home schooling matriarch.

While the core conceit is sort of cute, Razooli really can’t direct actors who aren’t already seasoned with prior experience. That means Ferro and terrifyingly competent scene-stealer Lorelei Mote have to carry the show while nearly everyone else puts in what are, to be honest, shockingly bad performances, and that includes the adults too. Perhaps part of the problem is that the whole sorry mess is filmed on 16mm stock instead of digital, which might have limited how many takes could be shot. A truly bizarre dance sequence near the end lifts the film’s game but it’s not quite enough.

• Riddle of Fire is on the Icon Film Channel from 6 May, and in UK cinemas from 7 June.