In the last fifteen or twenty years, which actor do you go to for deranged and unhinged? Nic Cage? Jack Nicholson maybe? Actors who were wild in their youth tend to mellow with age, or grow old disgracefully. In the case of Michael Keaton it’s been quite some time since he last danced with the devil in the pale moonlight, so it was high time he returned to cinema. Here he’s channelled his talent into creating a character that has to be on a par – in terms of being washed up and on the last roll of the dice career wise – with Mickey Rourke’s character in The Wrestler.

And whilst the aforementioned film was on the serious and dramatic end of the scale, Birdman comes at things from a quirky yet melancholy point of view. Dark? Yes. Supremely odd? Check. But still a drama, with comedy elements aplenty, taking the time to explore some interesting themes along the way.

In terms of setup we start with Keaton’s Riggan Thomson (great name), a faded movie star, one famous for playing a superhero called Birdman. He yearns for recognition again and, perhaps even more than that, credibility and critical acclaim. In short, he longs to be taken seriously as an actor. And in the theatre he might just achieve that. However this is his last roll of the dice, as his lawyer and friend Jake (Zach Galafianakis) regularly tells him.

To help his credibility he drafts in a proper theatre actor daaahling, in the form of Mike Shiner (Ed Norton), who then proceeds to steal his limelight on stage and seduce every nearby female he can. This begins to push his buttons – or at least twiddle Riggan’s sanity lever till the dial gets a bit loose.

As a result he is barely holding the play – and himself – together as they approach opening night, and to add to his woes he has: a daughter, Sam (Emma Stone), fresh out of rehab and with whom he is failing as a father; a highly strung actress girlfriend Laura (Andrea Riseborough) using her sexuality as a weapon; another highly strung actress, Lesley (Naomi Watts) who craves a similar level of artistic accomplishment; plus theatre critic (Lindsay Duncan) out for his blood and determined to ruin the play.

Alejandro Gonzalez Inarritu is a most interesting director. And a most interesting choice for this film. In the past he’s gives us Amores perros, 21 Grams, Babel and Biutiful. All pretty weighty tales. He tends to get drawn to exploring death and grief and how we deal with it.

With Birdman, whilst this is the first time he has tackled comedy, these morbid elements still get thrown into the mix. And as we know comedy and tragedy are often close bedfellows at the best of times. One treads a fine line alongside the other.

On the evidence of this film perhaps he should stick to this approach for the foreseeable future, as he has a knack for it. He also gives us a great sense of the mad, chaotic world of backstage. Indeed, behind the scenes of the theatre are a claustrophobic place, all cramped tunnels and confusing corridors. His camera often right on the shoulders of his cast, twisting and turning and swirling around them as the fight, argue, flirt and despair.

You particularly get a sense of this from Riggan. As he moves through the back corridors of the theatre accosted and confronted by his team, we follow him closely. At the same time we’re subjected to a musical score that matches the madness, namely a lunatic on a drumkit. It’s entirely possible this isn’t the film’s score, but the soundtrack to Riggan’s unravelling mind. (Actually, that’s still a score, even if it is internalised to one character. See… the madness is affecting me!)

The way Riggan’s alter ego (or subconscious) is personified and harangues him throughout the film slightly puts you in mind of Tyler Durden in Fight Club. Yet here it’s more of a peripheral presence, as Riggan wrestles with the inviting notion of celebrity and recognition versus the tough and uncompromising road of critical acclaim.

Whilst this is Keaton’s movie by some distance, the supporting cast steal every scene they get. Simply put, they all looked just plain up for it. Considering Inarritu’s past work it seems he’s been storing a world of mischief up his directorial sleeve. Ed Norton, Andrea Riseborough, Naomi Watts, Emma Stone… They all get to shine in a scene or two and are all an utter delight. It seems Inarritu has been supping from the cup of quirk formerly held by Wes Anderson. So in that respect it’s refreshing to see another director flourish and take up the mantle. (After Grand Budapest Hotel I feel Anderson may have got a little too quirky for his own good.)

I went into this film with no expectation or knowledge of the plot. I’d not seen the trailer. I knew the cast, but not the fact it was this director. Going by the title you might expect some sort of comedy featuring a shabby superhero. You could call it that. You could. But it wouldn’t be accurate.

You could say this film flies the flag for character driven pieces, whether that’s cinema or theatre, it favours people and emotions over spectacle and explosions. It takes a thinly veiled dig at blockbusters, but also against the rather ridiculous and overblown world of theatre. And it’s all the better for it.

This film is clearly one that critics will love (for those that haven’t reviewed it already) but, without going out on too much of a limb, it should also be one that audiences will love. And it will most likely be a slow burner as word of mouth spreads. This one will last, people will say. And, in that, Riggan (and Keaton) will be remembered.