In 2001, the American Samoa football team achieved hideous immortality by sustaining a world-historically awful defeat, going down 31-0 to Australia. Ten years of hurt followed with no appreciable improvement, and then the team hired a foreign coach with his own issues: the troubled and hot-tempered Dutch-American Thomas Rongen whose unofficial brief was to salvage American Samoan honour with a single goal.

Mike Brett and Steve Jamison’s 2014 documentary about all this, Next Goal Wins, is a much-loved heartwarmer. Maybe it needed a fiction-feature comedy remake and maybe it didn’t. But director Taika Waititi and co-writer Iain Morris have done one anyway, and the result, though necessarily sacrificing the stranger-than-fiction value of the documentary, is broad, affectionate and often funny in a goofy way. But the underdog sports comedy genre can’t really absorb the devastating revelation of tragedy that this real-life story contains (not to have included or acknowledged it, however, would have been a misstep).

David Fane plays the outgoing useless coach Ace; the team’s gifted trans player Jaiyah is portrayed by non-binary actor Kaimana; but the film’s most startling casting choice is Michael Fassbender as Rongen, an actor known for his brutally non-comedy roles and currently playing the killer in David Fincher’s The Killer. Fassbender isn’t Ricky Gervais and he isn’t, say, Chris O’Dowd. But like the intensely committed professional actor that he is, Fassbender works hard to fabricate a comedy performance and more or less makes it work.

In a way, the odder turns are from Elisabeth Moss and Will Arnett as Rongen’s ex-wife and her new partner who are tonally very uncertain – but then that sombre backstory was always going to cause them difficulties. The whole film is a little rough-and-ready in the way it’s put together, but it’s amiable and well-intentioned and the laughs are real.

• Next Goal Wins is released on 26 December in UK and Irish cinemas.