There's no grand subtext or archetypal theme here, unless you think Tommy Wiseau's real-life story translated directly into another gilded follow-your-Hollywood-dreams parable. Like generations of actors, directors and writers before him, Wiseau wanted to conquer tinseltown, and the only reason to lionise him for doing so is because the proof is in the pudding – we talk about him years later the same way we do anyone with anyone from Orson Welles to William Castle.

The only difference in this tale is that Wiseau, if you know anything about strange, underground or independent film, made a classic so bad in The Room it's right up there with Showgirls, The Rocky Horror Picture Show and a handful of other midnight cult movies we've come to love for what they represent as much as what they are.

How couldn't you love the lazy-eyed, creepy-looking guy who's obviously from Eastern Europe rather than New Orleans like he claims, who's obviously 30 years older than he claims and who made a movie through brute force despite not having a shred of talent? Aside from the personality quirks, what else is Tommy Wiseau but Ed Wood for the digital age?

As director and star, James Franco brings Wiseau's costar and friend Greg Sistero's book (which gives the film its name) about the making of The Room to the screen in a pretty straightforward fashion with a minimum of fuss, a lot of laughs and more than a little bit of love for anyone who believes in themselves this much – some would say you need to be this insane to make it in the movie industry.

We meet Tommy through Greg (Dave Franco), attending an acting class in his native San Francisco and seemingly too nervous and unconfident to be thinking about doing such a thing for a living. Tommy gets up to do a scene from A Streetcar Named Desire and overdoes it to a degree that makes him look like a complete maniac, but it's like a thunderbolt for young Greg, who can only wish he had the older man's confidence.

He approaches Tommy for advice and the latter attaches himself to Greg like a limpet. Tommy insists Greg read scenes in the middle of a diner, starts calling Greg his best friend, and when he casually drops the bombshell that he owns an apartment in LA and they should go down there and try to make it as actors Greg is dumbfounded, barely stopping to pack before heading off.

A few months later, not much has happened in either of their careers so Tommy decides to write the 'Tennessee Williams-level drama' we all know and love, casting himself as romantic lead Johnny and Greg as Johnny's best friend Mark.

Tommy is fixated on his story and authority over it no matter how little he knows about making movies, has seemingly endless funding as his disposal (another part of the real-life Tommy's mystique), and proceeds to morph into a tyrant among the middle-tier for-hire crew he's engaged for the production.

Towards the end of it all Greg's patience runs out. He's tired of handling Tommy's errant behaivour and after what they've all witnessed, it's obvious The Room is going to be a monumental turkey they'll all hope is quickly forgotten.

But Tommy's not done believing yet. Months later still when Greg has cut off contact with his former friend and is driving around LA still looking for his big break, he sees the infamous poster over Highland Ave touting the finished movie (and which contained Tommy's own phone number in real life). Greg can't help but be won back over by his former friend's determination, and the first screening goes anything but the way everyone espects, becoming The Room's first step toward what it is today, 15 years later.

Franco Sr is great as the contradictory Tommy, as impossible not to feel for as he is monstrous to the people around him, so secure in an imaginary world in which he's the epicentre that even the most outrageous things about him (like claiming he's studying under the great - and dead – Constantin Stanislavsky) are hard to dispel. He has the voice and the facial expressions down pat and the fact that he made the whole movie in character makes sense for continuity in what they were all doing rather than it being Daniel Day Lewis-level pretentious.

His younger brother Dave is less successful as Greg Sistero, trying a bit too hard with the affable, wide-smiling 'okay-but-I-can't-believe-I'm-doing-this' shtick. But it's a minor quibble – the rest of the cast from Alison Brie as Greg's girlfriend to Seth Rogen as the production company script supervisor all play it very real, and it's fun to see faces from Jason Mantzoukas and Jacki Weaver to Sharon Stone and Zac Efron (plus a who's who of Hollywood types playing themselves).

It's also a strange example of symmetry and how Hollywood eats itself. Tommy Wiseau came to Hollywood believing himself the next James Dean, a real life figure played by James Franco early in his career.

The one down note is that serious awards buzz quickly sputtered when claims of Jamaes Franco's sexual harassment emerged (like another movie I reviewed recently – Noah Baumbach's The Meyerowitz Stories). If he did so he deserves nothing more than all the plaudits from this film stripped from him, but it's another example of how great art can come from terrible people. It shows a Hollywood story as legitimate as those of Quentin Tarantino or Alfred Hitchcock, and the good natured love of its subject despite his dark side is a celebration in the truest sense of the word.