Right out of the gate, I have to say: this is the most impressive IMAX showing I've ever been to. Apparently the original film recording was shot/edited in a specific, weird aspect ratio, which made it almost square. Projected onto a screen the size (and quality) of the BFI IMAX was quite remarkable, and a level of immersion that I think will be hard to top. That said, I think if I were to see this in a regular cinema – or at home – it would probably fall just under a full 5* rating; that extra impact really does make the difference.

Even without the gimmicks though, this is a remarkably effective movie. Right from the opening sequence the stakes and gritty realism are dialled up to twelve, and they never really let up. Yet at the same time, the film does find moments to breathe and hone in on the individual stories that are being focused, allowing you to sit in the more human moments nicely, rather than merely being explosions, gunfire, and death for two solid hours. That balance – between the epic and the personal – helps the film flow nicely and really allows the cast to shine.

And what a cast it is, with nary a lacking performance amongst them. The big names like Tom Hardy and Kenneth Branagh deliver what you would expect – though Cillian Murphy's shell-shocked trooper was an unexpected curveball – but it's the "kids" that really shine. Whilst Harry Styles stole the headlines (not undeservedly, it has to be admitted; he was fantastic in this role, particularly on the train at the end), he's paired off nicely by the determinism and level-headedness of Fionn Whitehead, and the incredibly emotive performance of Aneurin Barnard, who manages to get so much into his scenes despite the fact that he has a single line in the entire film (what with being a French soldier trying to escape to England). I also have to say that Jack Lowden (RAF Pilot #2) does a brilliant job alongside Hardy, and really holds the pivotal final action sequence together on the boat with Mark Rylance. It's all stunning work!

All of which is elevated by the way the film is shot, which is subtle but genius. I could have done without the time skips – keeping it linear doesn't feel like it would have changed much – but otherwise the framing of scenes and overall pacing are expert, possibly some of my favourite work that Nolan has ever done.

Which then leaves us with the plot, and it's here that perhaps the film doesn't quite deliver what I had been hoping for. Don't get me wrong, I think the multiple narrative threads are done well, and it does a fantastic job of highlighting just how dire the circumstances in Dunkirk were, but I would have loved the civilian flotilla to have had a little more impact, a little more attention. That just wasn't the story Nolan wanted to make, and that's fair, but it's hard to set aside expectations like that entirely.

Still, the end result is an incredible movie, easily up there in the top ranks of war films of all time, and remains an incredibly moving homage to the thousands that lost their lives in one of the most infamous military evacuations of all time. It certainly had me in tears multiple times over, and certain scenes will stick with me for a long time (Hardy's final gliding descent; the first shots ringing through the stranded boat's hull; Brannagh's teary eyes as he walks down the pier asking people where they're from).