The status of superhero films as the defining movie of the 21^st century thus far brought with it the promise of genre diversification. After all, beyond a link to graphic novels and a smattering of superpowers, there’s not necessarily any one trait defining the genre. So when donning a cape practically guarantees healthy box office receipts, it’s reasonable to expect that by 2019 – nearly two decades after the success of X-Men, and well into the reign of the Marvel Cinematic Universe – we’d start to see a different kind of superhero film emerge.

By and large, that hasn’t happened. Oh, Marvel Studios promised big things early on; Captain America: The Winter Soldier was supposed to be modelled on ‘70s conspiracy thrillers, while Guardians of the Galaxy was apparently a superhero space opera. Yet each hewed tightly to the three act, three setpiece formula, and earned enough money to ensure that the closer we got to anything experimental was Taika Waititi getting to transplant a few of his jokes into proceedings. A few films feinted at post-modernism, but movies like Hancock, Kick-Ass and Super felt culturally premature while Deadpool eschewed any interrogation of the genre for masturbatory in-jokes.

Joker is the first film to deliver on the promise of a different kind of superhero film, offering up a character study of a twisted man absent any kind of action-packed setpiece. This is a film with a slender connection to its comic origins – it’s set in Gotham, and features both its eponymous, iconic supervillain (introduced as Arthur Fleck, played by Joaquin Phoenix) and the Wayne family – with less interest in CGI setpieces than stealing from Scorsese. Yes, the trailers weren’t misleading; Todd Phillips’ Joker is a feature length homage to Taxi Driver and The King of Comedy, right down to casting Robert De Niro (as pretty much Jerry Lewis in the latter film) and recreating the New York garbage strike that lent Taxi Driver its malodorous vibe.

Essentially, Joker is what you get when someone who grew up fetishising New Hollywood is given free rein, a reasonable budget and an identifiable IP. As a big fan of Scorsese’s oeuvre, I’m not entirely opposed to this. Judged purely as a work of imitation, there’s much to admire. Phillips’ version of Gotham City is an effective recreation of New York: all grimy streets and profane graffiti, porno theatres and the ever-present threat of violence at every street corner. Lawrence Sher’s cinematography unashamed emulates the grainy, under-exposed look of ‘70s cinema (despite being filmed digitally, it’s being screened in 70 mm in a special run at certain theatres – go figure). For a man who cut his teeth on comedies like the Hangover trilogy and Road Trip, Phillips’ work here – from a production perspective, at least – is surprisingly successful.

Of course, movies are more than their production design. Joker suffers not so much from a lack of ideas than their simplicity. Travis Bickle and Rupert Pupkin were fascinating figures: at once villainous and sympathetic, ambiguous and overt, repulsive and charming. One could hypothesise about the possibility of Bickle suffering from post-traumatic stress disorder, or attempt to diagnose Pupkin’s damaged psyche… but these weren’t straightforward characters to be plopped onto a psychiatrist’s couch, but contradictory creatures crammed with metaphorical meaning. Fleck is fascinating, but more straightforward, rendered with the kind of backstory endemic in supervillain origin stories: mental illness (realised, in true Hollywood fashion, in remarkably convincing delusions), a neglectful mother, a history of abuse.

Fleck’s problems are placed at the feet of an underfunded social services system, with his turn towards escalating violence coinciding with the cancellation of his therapy sessions due to budget cuts. Representing such austerity politics is one Thomas Wayne (Brett Cullen), whose campaign for mayor mirrors Charles Palantine’s arc in Taxi Driver. (Yes, that Thomas Wayne – we’re treated to an inevitable cameo from young Bruce, and the inclusion of a certain scene involving pearl necklaces and handguns late in the piece is representative of the film’s lack of restraint.) It’s idly interesting to align the rise of a supervillain with the decline of social services, but rather than allowing this subtext to evolve organically, it’s spelled out in intricate detail in the film’s final minutes.

That sort of lack of subtlety – lack of faith in its audience – is where Joker falls down. If this is supposed to be a thought-provoking film, then provoke your audience to think rather than spelling things out for them. Keeping a few things ambiguous – like, for example, the status of Fleck’s relationship with neighbour Sophie (Zazie Beetz) would allow us to unpack Phillips’ ideas. Instead, they’re outlined in exhaustive detail, and any glimmers of generosity that might lead you think that the film is smarter than it seems are smothered.

At least there’s Phoenix to shoulder the load. Fleck may not be written with the same complexity as Bickle, but he’s certainly more interesting than your average comic book movie protagonist – and played by a better actor than typically takes the reins of such films. Phoenix brings a real physicality to the role; he’s clearly lost a lot of weight, and his awkward contentions help sell the idea of Fleck as an outcast, physically uncomfortable within the confines of polite society. His utter commitment to the role makes him uncomfortable to watch – as this sort of character should be. Even as I lament the thinness of the film’s writing, it’s undeniable that it’s a genuinely disturbing film to watch, in large part thanks to Phoenix.

Joker has attracted some controversy, and Phillips’ half-baked responses to this reaction suggest, better than any evidence in the text itself, that there isn’t much below the surface here. On one hand, the film is a fantasy for the kind of violent offenders that realise their disconnection from society through mass killings at the like. Joker’s acts of violence provoke all-out riots, and he’s lionised as a revolutionary figure (even though he’s written as oddly apolitical). On the other hand, his profound unlikability means the film can be read as a rejection of such fantasy. It’s just a shame that Phillips clearly hasn’t worked out which side of the ledger he’s on, resulting in a film that’s as shallow as the more formulaic iterations of the superhero genre.