Greg Sestero (Dave Franco) is an under-confident but aspiring actor, struggling through drama classes in San Francisco. It is through the classes that he meets Tommy Wiseau (James Franco), a weirdly accented, long-haired eccentric who has more than enough confidence for both men. They move in together into Wiseau’s Los Angeles apartment to seek their fortune as Hollywood actors. When that plan fails, Wiseau uses his own mysteriously obtained fortune to write, produce, direct and star in a dramatic feature of his own: The Room.

The Room has been a real-life cult film phenomenon. It is widely heralded as one of the worst movies ever made, combining a surreal screenplay with weak direction, poor production values and jaw-droppingly awful performances. It screens regularly around the world to packed audiences of jeering hipsters, a full 14 years after Wiseau first released it. Now, in a relatively odd film project – and just as Wiseau wrote, directed and starred in a film with his best friend, James Franco has written, directed and starred in a film about the making of The Room with his brother Dave and his close friend Seth Rogen (who also co-produces). On top of that, it’s actually excellent: well-observed, nicely paced and wonderfully performed.

The key to the film is sympathy. It’s pretty clear that for most fans of The Room it is a viewing experience based in mockery: its audience enjoys it because it is so awful. It would have been very easy for James Franco to adopt a similar approach in writing and directing The Disaster Artist. Wiseau is a ridiculous figure: a wannabe movie star with a strange European accent, rolling in hubris but arguably devoid of talent. While the film does not shy away from making him a comic figure – that aspect is largely unavoidable – it also represents him as a man with genuine heartfelt aspirations. Through his performance Franco makes him a complex, elusive personality. We cannot explain away his behaviour, which is both childish and eccentric, but we can appreciate his vision, drive and ultimately his heartbreak when audiences laugh at his film. It’s a critical creative move, since it avoids turning The Disaster Artist into a hit piece. It treads a spectacular tightrope, making Wiseau a humorous character but, against all odds, a weirdly likeable one too.

Dave Franco is a solid viewpoint for the audience as the hapless Sestero, while Seth Rogen wisely plays things straight as Wiseau’s script supervisor turned assistant director Sandy Schklair. The bulk of the film’s cast wisely play things straight – there’s only really room for one over-the-top character in a film about Tommy Wiseau. Many of the film’s highlights come from some well-placed cameos, notably a restaurant encounter with writer/director Judd Apatow and a scene featuring Melanie Griffith as a drama teacher.

The obvious film which to compare The Disaster Artist is Tim Burton’s affectionate comedy Ed Wood, although it still feels a poor comparison. Burton’s film was bursting with affection from the first frame. The Disaster Artist plays things more dangerously: it’s fond of Wiseau for sure, but it’s also harshly critical from time to time, and regularly quite brutally funny. Believe it or not, this is Franco’s 14th film as director. I suspect it is also the one that is going to finally make audiences take notice of his rather intimidating range of skills.