In 2008, Jean-Claude Van Damme appeared as an unflattering version of himself in JCVD, a washed-up film star unable to find work who returns to Belgium and finds that a misunderstanding during a post-office heist helps revitalise his career. It’s a pretty good film, and there’s a lot of similarity between it and Birdman, which sees Michael Keaton playing an equally-unflattering version of himself as a washed-up former comic book film star trying to put on a Serious Play in a bid for relevance.

Keaton’s never had the career he seemed to deserve, his list of acting credits since the early ’90s just a series of unexceptional supporting roles and voice work. Birdman is his most interesting and potent performance since…God, maybe as far back as 1992’s Batman Returns. Here, he’s an empty husk of a man, the stress of the play, the despair of his failed career and damaged relationships breaking him down throughout the film as an imagined Birdman voice needles him. Just as good, and just as wilfully self-deprecating, is Edward Norton, strutting around the theatre as if he owns it and constantly threatening to upstage Keaton. It’s frequently a challenge to tell when the two of them are reciting lines from the play, from the film, or from reality.

Where Birdman stands out even more is in the smooth, gliding cinematography, all long takes and invisible cutting to give the impression of a single take. The camera itself is practically a character in its own right, albeit a mute and unseen one, eavesdropping on conversations and private moments, following people around the theatre and prowling alone through backstage corridors to find someone new to stalk. The freewheeling score is as much a character as the camera, an improvising jazz drummer providing a near-constant accompaniment. There’s a rapid pulse to the film that never quite stops. It’s exhilarating stuff.

Does Birdman actually have much to say about anything? Probably not. There are plenty of jabs at social media and its necessity for anyone wanting to be someone today, but it’s hardly a blistering broadside against it. Comic book films are referenced but left uncriticised. Theatre audiences and theatre criticism are both attacked but are also both pretty weak targets in the first place. There’s not a lot of subtext to the film; everything’s pretty much on the nose.

So, Birdman is softer than it might seem at first, but it’s so inventively and refreshingly presented that it easily gets away with it. The film is a great reminder of how good Keaton has always been when he has the material to work with, Norton is spectacular in his arrogance, Emma Stone as Keaton’s former-junkie daughter alternates between seething fury and nihilistic despair and Lindsay Duncan is beautifully sour as a theatre critic vowing to destroy Keaton’s play just out of spite. Even Zach Galifianakis is pleasantly tolerable for a change.

Looks good, sounds good, great performances, a witty and hilarious script. Birdman is wonderful.