After years of dilution and bastardisation, the phrase ‘cult film’ has lost almost all meaning. That is, except when it comes to The Room, the bad movie to end all bad movies. James Franco’s The Disaster Artist memorialises the making of Tommy Wiseau’s opus as recorded in Greg Sestero’s book, The Disaster Artist: My Life Inside The Room, the Greatest Bad Movie Ever Made.

Franco – who directed the film and appears as Wiseau (disguised under a heap of make-up and a thick, ambiguous Eastern European accent) – has an obvious affection for the film. The Disaster Artist begins with a serious of Hollywood talking heads extolling the virtues of The Room, in a clever mockery of empty awards-season praise. There’s a fine balance to be struck here. The movie, a comedy of sorts, clearly intends us to laugh at Wiseau – his alien approximation of Americanness, his odd affectations, his utter lack of shame – but it also wants us to recognise his twisted genius, his ability to create something unique in its awfulness.

For the most part, the film nails the balancing act this calls for. Our protagonist isn’t Wiseau, but Greg (Dave Franco), a handsome young aspiring actor who befriends the mysterious Tommy and moves to California with him. The first act of the movie forges the unconventional friendship between these two men as they strive unsuccessful to ‘make it big.’

As imagined by James Franco, Tommy is as American as it gets for someone so obviously not American: he’s arrogant and utterly convinced he’s destined for superstardom. Greg is more sympathetic – nervous, accommodating and, unlike Tommy, at least partially aware of his own imperfections as an actor. Together, they establish a bromance familiar to anyone who’s seen a Judd Apatow-produced film in the last decade; prickly and immature but fundamentally good-hearted.

Transforming the making of The Room into an Apatow-esque brom-com is actually kind of a genius move. Sure, it strips out some of the unconventionality to make the film more accessible to those unfamiliar with the source material – things like the excised vampire subplot or Peter’s unexplained recasting are avoided – but stories that are hilarious in print (like, say, Wiseau’s insistence on simultaneously shooting on film and digital) don’t quite land on the screen. Placing all The Room’s weirdness into a familiar subgenre while populating the film with recognisable comedic actors (Zac Efron, Nathan Fielder, Alison Brie, Seth Rogen, etc) actually accentuates the strangeness of The Room.

And Wiseau is perfectly suited for an Apatow-esque protagonist; his self-confidence, his weirdness, his immaturity all suit the brash manchild characterisation. Think a Danny McBride character with an odd accent. James looks to earn an Oscar nomination for the role at this rate. I’m not entirely sure he deserves it. It’s an excellent work of mimicry, but the screenplay’s appreciated insistence on keeping him unlikable throughout the second act limited any ability to evoke emotional authenticity for me. (In fact, I’d argue that Dave does better work as Greg, capturing the awkward uncertainty of someone coming to grips with their own mediocrity.) Awards aside, I can’t quibble with how well The Disaster Artist paints Wiseau, creating a character that’s at once sympathetic and utterly alien.

The Disaster Artist’s commitment to bromance conventions doesn’t always work. There are the systematic issues with the genre: this is about last film where I need to see Seth Rogen playing himself and offering sardonic commentary, or where female characters are almost entirely marginalised to focus on the male relationships.

The main issue for me – and it’s a comparatively minor one – is the film’s inability to stick the landing. Of course conflict arises between Greg and Tommy. Of course they ‘break up’ and of course they rekindle their relationship. But this emotional arc is so rushed that it feels utterly unconvincing; in one scene, Greg is sacrificing a huge career opportunity to support his friend, but within minutes they’re barely on speaking terms. Similarly rushed is the final scene, where within the space of one screening The Room transforms from reviled disaster to celebrated disasterpiece.

Such decisions are understandable evils in what must have been a tricky adaptation; while the ending doesn’t quite work, I don’t imagine a prolonged re-evaluation of the film over weeks and months would have been any more effective on-screen. What the film is really interested in doing and dissecting and celebrating the unique improbability of The Room’s very existence, and in that respect The Disaster Artist is an unqualified success. If you don’t really ‘get’ the phenomenon of The Room, this might not be for you, but for bad film aficionados, this is a must-see.