WHERE does art meet real life in Birdman, Mexican director Alejandro Gonzalez Iñárritu's wild and weird slice of blackly comic magic realism? In the air, of course.

Michael Keaton played Batman at the outset of the new age of superhero movies heralded a quarter of a century ago in Batman and Batman Returns, before the really big bucks came the way of such move franchises.

Now, aged 63, he plays Riggan Thomson, a washed-up actor,still famous/infamous for piously turning his back on his iconic superhero movie role of the Birdman. Thomson has swapped shallow, dumb Hollywood for the serious art of Broadway, where he is struggling to mount his own adaptation of a psychologically fraught and fractious Raymond Carver short story, What We Talk About When We Talk About Love.

You must suspend your sense of reality immediately and buy into Thomson's perception of the world. At the outset, he is levitating, legs crossed, in his underwear, with the gift/curse to move items by thought. If only he could have such an effect on those around him as he prepares for the calamitous previews ahead of the opening night.

The last vestiges of fame cling to him, and he is not prepared to let go entirely of its protective cape. However, Keaton's frazzled Thomson is not only fighting with his enervated if still itchy ego, but also his lawyer/producer (Zach Galifianakis) and his personal assistant, his ultra-assertive, rehab-flaky daughter Sam (Emma Stone), whose drug problems were triggered by his neglect and shows of overweening affection.

His cast is no easier to handle. Divorced Thomson is in a relationship of sorts with Andrea Riseborough's Laura, a tumble of confusion in her desire to have his baby but also make out with Naomi Watt's's equally insecure leading lady, Lesley. She, meanwhile, has brought her own boyfriend into the production, and while Mike Shiner may be box-office Viagra, there is frightening madness in his method acting.

Worse is to follow: there is always a voice nagging in Thomson's ear as a mental breakdown stalks him. If it is not cast, crew, family or attorney, it is the Birdman, heckling him invisibly or in his cast-off costume, as Thomson slips into hallucinations.

By comparison, the poisonous tongue of theatre critic Tabitha (Lindsay Duncan) is all too real in a bar-room clash as she vows to destroy him and his play.

By now, Inarritu's savagely satirical film has used Stone's Sam to mock the elitism of theatre in the age of social-media frippery, and Thomson himself to rail against reviewers and the 21st century brand of action-heavy blockbuster.

Birdman is breathless and relentless, unpredictable and fateful, filmed as if in one take in the dingy corridors and backstage warren of Broadway's St JamesTheatre in New York City. Inarritu is aided in this discomfort zone by the brilliant cinematography of Emmanuel Lubezki, who follows up his extraordinary work for Alfonso Cuarón’s Gravity by once again making the camera an extra character, an intrusive, prying eye.

Birdman is beautifully crazy, bravura film-making, taking flight as recklessly as Icarus and burning even more brightly.