Director: Zack Snyder
Cast: Ben Affleck, Henry Cavill, Jesse Eisenberg
Certificate: 12A

The ending of Man of Steel proved two things. Firstly, that superhero movies need to climax with something other than a gigantic object hurtling into a city. And secondly, that no matter how hard comic book movies may try, they often end up the same.

The spectre of 9/11 looms large over Hollywood - and it's perhaps no surprise that when tasked with coming up with something threatening and terrifying in scale, the attack on the Twin Towers is subconsciously called to so many writers' minds - a cultural act of catharsis, more than a commercial act of unoriginality. And so Zack Snyder's Superman film, like many sci-fi blockbusters before it, ended with a CGI monster battling a CGI monster in Metropolis, as skyscrapers toppled and innocent bystanders perished. Fans were in almost immediate uproar, some arguing that Superman would never let this happen and others that he was still young, he hadn't completed his Jedi training yet, and didn't know any better. The real issue, though, was that it was dull and repetitive.

But now, it looks like that travesty may have been intentional all along, as Snyder's sequel doesn't so much examine the aftermath as pick its way through the philosophical and ethical rubble, brick by brick. The opening set piece drops us right back in the middle of that punch-up, reliving each explosion alongside the people on the ground. It takes the bland, uninteresting spectacle of Man of Steel and gives it an emotional weight - retelling the narrative from the perspective of us puny humans, the concerns of gods waging war above us rendered alien, aloof and elusive. Subverting that cinematic trope, but also building an entire entertainment franchise - this is the first of DC's new, Marvel-style Justice League universe - upon post-9/11 trauma? It's the boldest and most intelligent piece of superhero filmmaking to date.

The problem is the rest of the film that follows.

Our guide through the decimation of Metropolis is none other than Bruce Wayne (Ben Affleck), who, it turns out, has a building in the city. Racing to save friends and employees, Superman and Zod's confrontation leaves him grieving, scared - and angry. And so he begins a lengthy quest to bring down the Superman, a person he regards as a threat to the whole planet. It's a genuinely brilliant concept, using the shock and fear caused by the catastrophic climax of Man of Steel to push Batman over the edge - and over the edge he certainly does go. Within the first hour, we see him not just using weapons and killing people, but even branding criminals using his Bat symbol - a mark that, we are told, is effectively a death sentence in prison.

Ben Affleck does well to make Bruce Wayne his own so soon after Christian Bale hung up the BatCape: his chiselled chin is stubbled and his eyes always glowering, more a vigilante than his predecessors ever have been. By the time he's crossing paths with Wonder Woman (Gal Gadot) and Supes himself, he's not only making the wrong judgements, but also making bad ones; this is a Batman almost unrecognisable from previous incarnations, one who's uncomfortable to watch in action. Deliberately so.

Superman, meanwhile, has to grapple with the idea of whether he is beholden to the human race's laws or not, as Lex Luthor (Jesse Eisenberg) pushes the public's buttons just enough to blow up any trust they once had in him. It's a refreshingly grown-up portrait of comic book characters, where, like Batman, Superman has become a corrupt idol - a literally monumental figure that has crumbled over time. He's a fallen god, dragged down, in part, by man, the kind of epic imagery that the script conjures up with repeated references to Prometheus and Milton. The age-old theodicy of God and evil swiftly flies in: If Superman is all-powerful, why doesn't he save everyone? Is that because he doesn't care? And if he is benevolent, does that mean he's not omnipotent and can't save everyone? Any mainstream popcorn-muncher daring to tackle such weighty theological topics is, frankly, to be applauded - in an age where superheroes team up, make jokes and advertise upcoming sequels, it's astounding to witness anyone attempting to something more meaningful with spandex and tights. Even the movie's most important weapon is a spear - a direct nod to classical mythology.

"Psychotic is a three-syllable word for any thought to big for little minds," argues Lex, gleefully.

The latter words certainly stick in your mind. It's rare for a superhero movie to think this big, considering the consequences of actions rather than just revelling in the actions themselves - comic book movies, in general, tend to look to the thrills of the present and the excitement of the future, rather than look to the past and take responsibility for it. In that sense, Batman v Superman is, on one level, a mature, impressive debate about the existence of god, the corruptibility of man and the importance of wearing appropriate clothing when punching deities in the face. On another, very real, level, though, it's also a mess.

That's because Batman v Superman: Dawn of Justice is, by its very nature, the cornerstone of DC's new universe - and that means it needs to fit in Wonder Woman, meta-humans and hints of other characters who will presumably become important at some point. To cram them in, though, it has to sprint everywhere, from teasers of lab experiments to photos of Wonder Woman in action decades ago. While the building up of the implausible rivalry between its two titular heroes is well handled, everything else becomes ridiculous, with the screenplay's jumpy approach often feeling incoherent rather than intriguing - with Snyder talking of deleted scenes from the two-hour-and-a-half runtime, and a smattering of unexplained nightmare sequences, it's an understatement to say someone got carried away with the editing scissors. "What's going on, Alfred?" Wayne asks his dependable butler at one point. "How best to describe it?" comes the reply. And how.

While Cavill and Affleck (and Gadot, who gets little to do other than smile and skid around on the ground a lot, but does it brilliantly) are all good, the rest of the ensemble therefore struggle to make an impact. Jeremy Irons' Alfred is amusing, but apparently not that concerned about his master's lapse in ethics, while the usually-excellent Jesse Eisenberg as Luthor delivers the worst villainous performance in a movie since Eddie Redmayne in Jupiter Ascending - his Lex speaks on constant fast-forward, giggling, making literary allusions and desperately trying to sound unhinged at all times, just in case the jagged violins on the soundtrack don't spell it out for you. One scene where he recites "ding" over and over is laughable, rather than threatening. And what of Amy Adams? Lois Lane has little more to do here than throw an object central to the plot in a puddle of water - and then, five minutes later, meekly return to pick it up again.

It's a dumb moment that sums up the whole of Batman v Superman - a movie that dares to do something unpredictable and brave, only to realise, too late, that it's gone wrong. The film isn't a total disaster, but it never quite manages to bind together its disparate ideas, each of which are duking it out, like its titular heroes, to become the centre of attention, only for the mother of all coincidences to bring them together. Is it Lex and his love of alien tech that we should worry about? Wonder Woman and her magical shield? The tyranny of gods and the futile plans of mice and men? Rather than follow through on its ideas, the movie retreats to disappointingly safe territory, and we descend once more into a CGI-fest that feels dull and repetitive. (When your climax recalls 2008's The Incredible Hulk, you know you've not succeeded.) The director's visual spectacle matches his epic ambition, but how fitting that Snyder's reach should exceed his grasp so tragically. And how humbling that man's lofty ideas about gods and myths should fall, Icarus-like, back to the dusty ground. Someone could make an interesting superhero blockbuster about that. On second thought, maybe not.