There’s been a wealth of conversation recently about the increasing homogenisation of superhero films: Matt Zoller Seitz kicked off the discussion with his piece on “Things Crashing Into Other Things” and I can’t dispute his points. Even if you enjoy most of the new wave of big budget superhero pictures, it’s hard not to notice that they’re all fundamentally structured the same way: “four action setpieces strung together with exposition and iced with a tease” (as David Ehrlich puts it).

X-Men: Days of Future Past is very much in that model of a modern blockbuster, down to the inevitable post-credits teaser. What distinguishes the film isn’t an originality of structure or aesthetics, but rather a commitment to using the superhero formula as a medium for entertainment and a robust consideration of character and complex themes. It’s not that these elements are missing from its contemporaries – Captain America: The Winter Soldier competentlyaddresses character and political subtext, as have many post-Nolan superhero films – but that the screenplay ensures the action sequences are (mostly) an extension of characterisation and theme, rather than a distraction.

Days of Future Past opens in a dystopian near-future, where adaptive automatons called “sentinels” have enslaved or murdered the majority of the mutant population. The few surviving mutants – Kitty Pryde (Ellen Page), Bishop (Omar Sy), Storm (Halle Berry), not to mention Professor X (Patrick Stewart), Magneto (Ian McKellen) and Wolverine (Hugh Jackman) – eke out a perilous existence avoiding sentinel attacks thanks to Kitty Pryde’s time travelling techniques. These are demonstrated in a memorable opening sequence, a special-effects-laden encounter that borrows heavily from the introduction to The Matrix.

After some clunky exposition for those in the audience unfamiliar with the previous X-Men films, Wolverine is sent back to the 1970s to try and prevent the chain of events that led to the Sentinel Program. To put a twist on the “would you kill Hitler” time travel mainstay, Wolverine must convince a younger Professor X (James McAvoy) and Magneto (Michael Fassbender) to prevent an assassination: that of sentinel inventor, Bolliver Trask (Peter Dinklage), whose murder at the hands of Mystique (Jennifer Lawrence) set into motion a chain of events that ends in the aforementioned dystopia.

It’s a tricky narrative, juggling a couple timelines and countless characters, but it’s carefully constructed, consistently coherent and capable of surprising the audience. The future scenes are a distinct chink in the film’s armour; they continue to crib from The Matrix, right down to the blue-light-disco colour scheme, and lack any substantial characterisation or tension. It’s all fan service and special effects. Thankfully, we spend the majority of our time in the past, where the film uses the backdrop of the end of the Vietnam War to stage some spectacular action driven by thoughtful moral conflicts.

Where the previous X-Men films have divided their attention between a dozen or more characters, Days of Future Past narrows its attention on three in particular – Magneto, Mystique and Professor X – with the remaining characters left to coast on their not inconsiderable charisma (or, in the case of Hugh Jackman, some freakishly veiny muscles). It’s a clever choice. Not only does the tighter focus allow for more substantial character arcs, it allows the film to work its thematic skeleton – a consideration of the morals of warfare – into an ideological love triangle of sorts.

Professor X stands at one vertex with an enduring faith in the goodness of humanity – a belief that they can be convinced to do the right thing. Magneto is philosophically opposed, certain that humans’ fear of mutants will only manifest itself in devastation that must be prevented through whatever means necessary. Magneto has always been one of my favourite fictional characters thanks to the complex contradictions at his core, as a man who lived through the Holocaust but now believes in the total superiority of his own race. Days of Future Past is the first X-Men movie to really get Magneto right, largely thanks our glimpse of this terrible future. It’s easier to sympathise with his take-no-prisoners attitude when we’ve seen the ramifications of doing nothing. His commitment to his agenda is made terrifyingly clear in a mid-air confrontation with Xavier, a showcase of both Fassbender’s acting and Magneto’s anger.

Perhaps Mystique would not have been so prominent in this sequel had First Class not stumbled onto the Jennifer Lawrence. She is so fundamental to the film’s central theme while building on character elements from First Class that it’s hard to imagine Days of Future Past working without her. Mystique is torn between Magneto and Xavier’s philosophies, believing she must do what is necessary to protect mutants but without Erik’s cool pragmatism. She is as much motivated by retaliation (Trask is responsible for her friends’ deaths) as dogma. In fact, Mystique also has much in common with Trask – each is given an impassioned speech where their violent actions are couched as necessary to prevent further suffering, with Trask referring to the tens of thousands who died in Vietnam.

Vietnam is an important backdrop to this film. We visit Saigon in an early scene, and the film is set during America’s withdrawal from the country. This is a war that was inspired by mistrust in others, and while the parallels between the decisions of the United States – decisions motivated as much by politics as a need to retaliate for the deaths of their soldiers – and the choices facing Magneto, Mystique and Professor X are abundant. Significantly, the action sequences in this film are rarely there just for the sake of action; not just goodies versus baddies. Instead, the conflicts are based around moral decisions rather than simply the clash of superpowers. It elevates scenes that would otherwise have blended with the countless other special effects showdowns we’ve seen over the past year.

These grim themes are perhaps to be expected in an era of filmmaking where comic book movies are expected to be “dark and gritty.” Certainly Days of Future Past is not a generally lighthearted film; these are weighty subjects and they are approached with gravity when necessary. But there is humour, too, and excitement. Quicksilver (Evan Peters) provides both, as a young speedster who’s undeniably the best thing about the film. Bryan Singer’s presentation is generally conventional – adequate – but an action scene centring on Quicksilver set to the strains of Jim Croce’s “If I Could Save Time in a Bottle” is astounding and unique.

Ultimately, what made me enjoy X-Men: Days of Future Past so much was not its special effects, nor its acting, nor its script, nor its thematic concerns. Rather, in an era of filmmaking where Superman is presented as a murderer and third acts are dominated by en masse destruction, it’s refreshing to see a blockbuster whose fundamental philosophy is optimistic and life-affirming. Days of Future Past may lack originality, but it’s one of the best executions of the superhero formula yet.