Ninian Doff has previously been better known as the creator of music shorts for artists including Royal Blood, Migos, Miike Snow and Chemical Brothers. Now he's created Boyz in the Wood, his debut feature in which a quartet of lads attempting to gain their Duke of Edinburgh Awards in the Highlands become unwitting fodder in a deadly game of cat-and-mouse with Eddie Izzard's scary huntsman.

Set to be a cult classic, this South by Southwest audience award-winner is an outrageous and dark coming-of-age comedy with added hallucinogens and fun trippy scenes. To tell us more about it, we're on a conference call with the four young lead actors: Rian Gordon, who plays macho loose cannon Dean; Lewis Gribben, the less-than-sharp Duncan; Viraj Juneja, an aspiring rapper DJ Beatroot in impractical white trainers; and Samuel Bottomley as Ian, the only one who actually wants to be there.

'They auditioned loads of kids,' recalls Gordon. 'So they put us in groups of four, took us out to the woods and got all freaky with us.' Freaky how? 'Mind now Rian, we'll be getting sued!' laughs Juneja.

'Nah, we just went to Film City [in Glasgow], took us out into the park in fours and just shot loads of full scenes,' recovers Gordon. 'I think by the time we got the jobs, we'd learned eight or nine full scenes.'

The film is a lot of fun, but was the shoot as entertaining as it sounds? 'No, was it fuck! It was mental!!' bursts out Gordon. 'Six weeks on location up in the Highlands; Viraj had Nikes and I had binbags. It was like World War I. Getting shot at!'

The chattiest of a chatty bunch, Gordon echoes the raw Scottish delivery of Dean. 'Midges,' chimes in Bottomley in his dry Bolton accent. 'Aw man, I've never seen as many midges!'

The one doing the (pretend) shooting was Eddie Izzard, one of the more experienced actors in the cast alongside Kate Dickie and James Cosmo. 'Eddie was intimidating, man, I didn't know how to speak to him,' says Gordon. 'He was in character and he looked terrifying; his eyes are piercing.'

Juneja says Izzard kept the character going off-camera. 'We were sitting eating lunch and he was pointing his gun at us! Nah, not really. But I spent a bit of time with James Cosmo when we were doing our scene at two or three in the morning, and he'd tell me some of his stories: it was just incredible.'

Adding to the film's Scottish flavour is its soundtrack composer Bobby 'S-Type' Perman, working here on his first feature after commercial work for Nokia, Adidas and Cadillac. 'I love working to pictures,' he explains, of how he came up with the rap beats he's composed. 'I find having the visuals in front of me before I touch the keyboard really fulfilling. I'm not so keen on working to a written brief, where it can be tricky to gauge a mood.'

The film's mood is generally dark and tense, epitomised by a pivotal five-minute scene which starts off as a rap number. 'It develops into a whole movement, adding tension as the scene progresses,' says Perman. 'I really enjoyed the collaborative aspect, going back and forth with Ninian, developing rough ideas into full pieces to drive the different scenes.'

The young actors are thrilled with the film's early success. 'Especially for Ninian,' says Gribben, 'because this is his first film and it's done so well. What that means for his future is endless, he's such a great writer and director.' The actors believe the full process – from entering pre-production to completion – was as little as a year, which is a significant achievement. 'Folk keep asking us what our ambition is for it,' says Gordon. 'I just want it to win five Oscars: that'll do!'

Boyz in the Wood, Festival Theatre, Edinburgh, Wed 19 Jun.