Ron Swanson admires Alejandro Gonzalez Inarritu’s latest film, which is released today.

Chances are that you already have an opinion on Birdman. It seems to have featured in nearly every US critic’s end of year roundup; has been discussed by the UK’s prolific film tweeters since it premiered at the Venice Film Festival; was in the news again as the LFF’s Surprise Film in October; and is one of those avowedly independent releases that has a major studio-sized marketing spend and a concept so high that it appears to be everywhere.

That impression may come from the fact that this is an Alejandro Gonzalez Inarritu film, and that comes with some baggage. There are few more distinctive directors (for his supporters and his critics alike) than Inarritu, whose signature style (fractured narratives, jumpy edits, A-list casts being miserable) and themes (grief, loneliness, stress and misery) have been writ large across his first four films. However, it would be fair to say that Birdman sees him amend his style, at least, even if he cannot abandon those themes entirely. Don’t let the fact that Birdman has been nominated in the Comedy/Musical strand of the Golden Globes fool you; it may be funny, but it’s not an altogether happy ride (at least not in the conventional sense).

Michael Keaton plays Riggan Thompson, a fading Hollywood superstar most famous for his iconic role as Birdman in a mega-franchise some twenty years before now. Thompson has put all of his capital (financial and otherwise) into directing and starring in his own adaptation of a Raymond Carver short story on Broadway. This is a familiar terrain for Inarritu, who has essayed desperate men throughout his career, marshalling superb performances from Sean Penn, Brad Pitt, Gael Garcia Bernal and Javier Bardem along the way. Keaton’s work is similarly superb, and Inarritu never really allows us to escape the feeling of stress and encroaching demons that begin to overwhelm Riggan.

We know that they’re overwhelming him, in large part, due to the brilliance of Keaton’s work, but also because of two key stylistic decisions that Inarritu made, which go some way towards differentiating the film from his previous work; the way the film is shot, and how it is soundtracked. Emmanuel Lubezki’s cinematography is tricksy, impressive and integral to the way in which Inarritu chose to tell the story. Lubezki and Inarritu have designed the film to appear to have been filmed in one continuous, weaving, dizzying tracking shot. Like Rope, the film is largely set in one place (the theatre, rather than an apartment) and this effect is achieved by several long takes being edited together to appear continuous.

It’s a vertiginous place from where to start, but it is absolutely not a gimmick. Instead, the impact is meant to mirror the mental degradation of our central character, upon whom stress after stress is being inflicted, with seemingly no respite whatsoever. That effect is amplified by the score, entirely played on the drums, by jazz musician Antonio Sanchez. Sanchez’s drumming is noisy, discordant, enervating and seemingly ever-present. It’s the antithesis of a film score designed to answer questions of characters’ motivations; instead unsettling and ratcheting up the tension for the audience.

Inarritu’s film is a challenge for the viewer, almost engaging in a stare-off with the audience, daring them to blink and find an easy escape from Riggan’s story and the stories of the supporting characters who surround him. In Inarritu’s previous films he attempted to create a feeling of helplessness and bewilderment by cutting away from characters and stories at crucial moments, obfuscating traditional narrative, and leaving the unease of the lack of resolution hanging over the head of the audience, while throwing you headfirst into someone else’s problems. In Birdman, Inarritu’s focus is rarely, if ever, away from Riggan.

He’s created, with the help of a super supporting cast, a coterie of fascinating background characters, yet as this is Riggan’s story, they’re there, for the most part, to add to his stresses, test him or highlight his narcissism, often all at the same time. In fact, the cast do a tremendous job of making the background characters into people you’d happily watch more of.

Only rarely do you see them interact with anyone unless Riggan is also there. It makes those scenes when that happens oddly becalmed, whether it’s a touching moment of sisterhood between the play’s two actresses, played by Andrea Riseborough and Naomi Watts, or two strange, soulful scenes between Ed Norton’s diva, theatre-superstar actor and Emma Stone’s recovering addict daughter. The two scenes between Norton and Stone take place on the roof of the theatre, and the percussion is replaced by the ambient sounds of downtown New York. These scenes allow us an insight into both characters beyond what their representations of themselves are to Riggan. It’s testament to the subtlety in both actors’ performances that they hit those notes so sweetly.

The film could only succeed, though, with something special at its centre, and Keaton gives a career-best performance as Thompson. He nails the character in his quiet, introspective moments (his two conversations with his ex-wife, a gorgeously judged turn by Amy Ryan), and in his rage; spittle-flecked outrage when confronting Lindsey Duncan’s theatre critic, who has decided that she’s going to kill his play, sight-unseen. In recent years Keaton’s been a scene-stealer (The Other Guys, Toy Story 3) but it’s thrilling to see him thrust front and centre in a hugely ambitious, intelligent film, one for which there could have been no better fit in the lead role.

I admire much about Birdman, notably the skill of all involved. Lubezki’s cinematography is astounding (as much for the level of planning in the dizzying tracking shots as the trickery involved in ‘stapling’ them together), as it was in last year’s Gravity, another very different challenge for a cinematographer. Inarritu extracts performances of the highest quality from his cast, while keeping the pace up, and the story building, Sanchez’ score is unlike anything else. They are all things to admire, but what I love is the film’s ambition and heart.

The ambition of the director to make a film that is so different from what he’s made before. The ambition in risking your film’s heart by using showy techniques and making them integral to the way you tell your story, or the decision to make a film that attempts to explain the madness that can come from success and failure, in equal measure, at different times.

Where Inarritu’s film finds an extra level of resonance is in its portrayal of art. Norton’s character is a tool, but he’s clearly a great actor, one who energises Riggan with his greatness. Riggan’s sacrificing of his sanity, his money, his friendships, his familial relationships could be seen as tragic, but there’s something heroic (if more than a little maniacal) in his determination to make his life’s dream happen. Inarritu isn’t interested, so much, in the quality of the end-product, but he clearly cares for people whose art causes them to suffer, causes them to bleed and lose.

That’s evident in just about every frantic, pain-filled frame of this fabulous film.