Suicide Squad is a feature length trailer. It’s structured like a videogame and plotted like a D&D campaign where everyone’s roleplaying chaotic evil. It’s a movie that flits between Jai Courtney downing a beer in the middle of an action sequence and Cara Delevingne gravely intoning arcane shit like, “You have returned my heart. Now I can complete my weapon.” It’s neither a disaster nor a masterpiece, but it is kind of a mess.

Brisbane’s preview screening for the film was amply stocked with sugar-laden treats. Neon-coloured choc-tops, purple lollypops, even colour-coated popcorn instead of the hot buttery kind. The intent seemed to be to give the attending audience a sugar rush; fitting, given the film itself opens with a hyperkinetic half hour so before the inevitable aftermath of too much sugar: the crash. Much like Deadpool, Suicide Squad itches to burn the whole superhero-structure down before reluctantly rebuilding it in its final act.

Anyway, I kinda liked it. Suicide Squad has a lot in common with the overstuffed, over-ambitious debacle that was X-Men: Apocalypse. But even that film’s good bits weren’t good; Suicide Squad’s swing for the fences is a bit of a mishit, but at least it connects. There are probably three major differences between those two films. The first is that Apocalypse is, for the most part, deathly serious; Squad ain’t (though it could stand to have been much less serious, nonetheless).

The second is that, in a rare exception in the superhero sub-genre, Suicide Squad doesn’t feel like it’s more about the last movie and the next movie than itself. There’s so much plot and so many characters here but they’re all in service of this movie; granted, that means that the characterisation isn’t quite as robust as its Marvel counterparts, but that’s fine given how broadly archetypal these [anti]heroes are anyway. It even manages to make the obligatory DC-universe cameos (hey, it’s the Flash!) not be shitty.

The third difference is the cast, who – with some exceptions – manage to sell this overblown absurdity with a thick dollop of charisma. Chief among their savours are Will Smith and Margot Robbie, finding a film that makes better use of their chemistry than last year’s wait-that-was-a-movie? Focus. Also Viola Davis is great as an utterly sociopathic government type, and Jai Courtney – who’s justly and regularly derided by the Film Twitter commentariat – delivers the sort of performance that would’ve justified his absurdly successful career (admittedly, in a very minor role).

There are other performances worth highlighting – Jay Hernandez lending a cultural cliché much-needed humanity, Ike Barinholtz dialling down his shtick to just the right level – but one that deserves attention for all the wrong reasons. While Cara Delevingne is bad here, it’s Jared Leto’s woeful mugging and mincing as The Joker that we must, sadly, dwell upon. His performance is all accoutrements, aimed somewhere between Jack Nicholson (moreso The Shining than Batman) and James Franco in Spring Breakers but falling well short of the mark. He has no menace, no sense of slender humanity beneath his blinged-out exterior. He’s a bore, a drag, a waste of screentime.

Similarly ill-advised is the choice to spend most of the last half of the film in an abandoned city (it’s Midway City, but to my eyes it’s strongly reminiscent of Gotham in Arkham City). You know how all the marketing amps up the colour, doubling down on the ‘90s-collage meets Tumblr-#aesthetic look? Well, the film itself too often embraces dreary set design and dreary action setpieces; oh good, it’s another faceless army of aliens or rock monsters or whatever that allow for PG-13-rated but utterly weightless fight sequences.

As much as I dug Suicide Squad, it’s not hard to imagine how the film could’ve been better. If you’re going to stick alien lighting effects in the sky, why not go full-Night-of-the-Comet and blanket the horizon with purplish-green light? And why not ramp up the comedic aspects? This isn’t a comedy per se, but it spends much of its runtime crying out for a lighter touch; at one point batches of the audience – either starved for laughter or just generally disturbed – burst into laughter at Batman punching a woman in the face. Haha … ha?

So, sure, by its final minutes Suicide Squad more closely resembles any other superhero movie, with redemptive character arcs and big CGI showdowns and tying things up in a loose bow for the next movie. (There’s even a mid-credits sequence that would feel like a parody of Iron Man’s “Avengers Initiative” scene if it wasn’t played so straight.) But while that sugar rush is going, it’s a hell of a ride.