Smartly timed for release in the week the 2015 Rugby World Cup kicks off, this breezy and joyous documentary offers an interesting take on a changing game. Written and directed by James Marquand (One Night In Istanbul), with sporadic narration from Brian Cox (the X2 actor, not the TV professor), it’s a worthy attempt to tell the remarkable story of the Pacific Islanders’ rugby side and their struggle for survival in a ever-more lucrative sport.

The Tongans, Fijians and Samons are players hewn from an ancient culture and an unforgiving landscape. Their speed and power has influence throughout the rugby world and playing against them is ‘like you’ve been in a car crash’, according to interviewee Jonny Wilkinson. But these tiny island nations face a battle to harness their raw talent against the huge wealth and resources of rugby’s biggest teams.

Through 93 odd humoured minutes, Marquand and interviewees including a host of Islander players past and present, and rugby legends like Wilkinson, Jason Robinson and Australia’s Matt Giteau (as well as, oddly, former boxer David Haye), explore the big personalities and historic victories of real sporting underdogs.

Fittingly for film focused on teams famed for their enthusiasm and excitement but less their discipline and organisation, Pacific Warriors darts back and forth between topics and World Cup memories, with no real thematic approach or structure. It prevents Marquand’s film feeling repetitive or dull but also makes the end product as a scattershot as a Fijian’s sidesteps. But with some heartwarming and hilarious reminiscences – a Tongan changing his name to Paddy Power to raise much needed sponsorship cash, Islanders’ addiction to KFC – insights from rugby’s leading lights and an inspiring look at a culture fighting to persist in a modern world, it’s a likeable and engaging film.

Pacific Warriors might not be a classic of the sports documentary genre, but has enough excitement, humour and heavy hits to be worth a watch as a World Cup warm-up. One thing’s for sure – you’ll be backing these indomitable heroes all the way. Pacific Warriors is out now on DVD and Blu-ray.