Robin Hardy's 1973 cult movie The Wicker Man, written by Anthony Shaffer, has attracted a following as a “folk horror” classic; there has also been an ill-fated re-make by Neil LaBute starring Nicolas Cage and an aborted stage adaptation three years ago.

Now, in her transitional phase between running the National Theatre of Scotland and succeeding Dominic Cooke at the Royal Court, Vicky Featherstone launches a new stage version by Greg Hemphill and Donald McLeary that redefines the islanders’ brutish paganism in the aftermath of a missing girl mystery as an unhealthy obsession with amateur dramatics.

This idea of limited ambition and cheesy appeal is clearly finding its target audience in the sleekly refurbished Assembly Rooms on George Street, and the NTS actors - led by Hemphill himself as the batty Lord Summerisle, Sally Reid as the lubricious Marie, cavorting in woolly “nude” suit, and Sean Biggerstaff as the new recruit from Glasgow’s thriving cultural metropolis (“Is it true there’s a Waitrose there?” Marie asks between lustful pants) - are rejoicing in their good luck.

I sat stony-faced throughout, I’m afraid, not so much out of a sense of humour bypass as a feeling of, well, yes okay, but why are they bothering? Coarse theatre am-dram jokes - collapsing scenery, posing ineptitude, coy knowingness - are funny for five minutes. Well, maybe ten. Ninety minutes is torture.

Spoof movie homage seems to be a sub-genre north of the border; last year’s hit send-up of Casablanca, a far superior piece of work, is back at the Gilded Balloon this festival, and well worth catching; as for The Wicker Man fans and completists, nothing a critic says will ever spoil their fun.