Utah faint

Here it is, then: along with The King's Speech, the other overhyped "first great film of 2011″ …

127 Hours. Like The King's Speech, it's British-made, Oscar-ready and based on a true story. Unlike The King's Speech, it mostly won't give you a warm feeling inside. On the contrary, you may spend much of its 94-minute running time squirming, groaning, shaking your head, feeling existentially miserable and, towards its climax, arching your whole body in your seat like I did, pushing your feet against the seat in front and stretching your neck behind the headrest. Yes, it's a film you will know you've seen after you've seen it. Unlike The King's Speech.

Danny Boyle, who directed it, and Simon Beaufoy, who co-wrote it with him, have not wasted a single drop of the goodwill afforded them after the success of Slumdog Millionaire. Having worked for years with Alex Garland, Danny seems to have found a new best friend. Their screenplay, based on Aron Ralston's bestselling account of what happened to him when he got his arm wedged behind a boulder in a canyon in Utah in 2003, is less about dialogue (although there is some), and more about the skilful ordering of events, and the judicious use of flashbacks and hallucinations, ultimately conveying the treacly passage of time and the churning over and over and over of the implications until a this-is-it decision is made.

Not sure if we need a SPOILER ALERT here, as Ralston's remarkable story came out in book form in 2004, and, thanks to the publicity around the film – and boy has there been a lot of publicity – it's back in circulation again. The film is called 127 Hours and even the most cursory precis will tell you that he's a sort of extreme thrillseeker who gets trapped in a canyon for 127 hours before escaping to write a book. Most articles and reviews I've read also tell you how he got out of there. For me, knowing what he did, in real life, is what powers the film. I had read about the real event in detail, and I went along to the film in the secure knowledge that Danny Boyle was going to show me that event, and that it would be at the end of the film. It's like going to see Titanic. Hey, or The King's Speech. It's not the destination, it's the getting there that counts.

In many ways, 127 Hours is pure cinema. It's as if someone set Danny Boyle an exercise: take this very specific true-life adventure, with one protagonist, stuck in one place, where time passing is a key element and most people know that he survives and has to do something pretty unusual to ensure that survival … and off you go! The blend of narrative economy and visual fireworks is brilliantly stirred: it's still and quiet and logical and practical and functional when it needs to be, and it's dazzling and jolting and imaginative and impressionistic and rollercoasting when it needs to be – and it needs to be both. Have you seen Gus Van Sant's Gerry, with Matt Damon and Casey Affleck? It's a useful point of reference: another film, a lot more loosely based on actual events but rooted in reality, in which two young hikers get into trouble in the great outdoors, this time wandering off the beaten track in Death Valley and getting lost. I guess the big difference is that in Gerry, the action is partly improvised, and it shows, in a good way and a bad way. Here, everything is tightly choreographed, and it pins you to your seat because of that.

James Franco is amazing as Ralston. He's onscreen the whole time, mostly stuck in his predicament, sometimes filming himself on a camcorder and even playing up for the camera, allowing us to read his mind when Boyle isn't actually showing us what's going on inside it. I had my doubts about Franco, especially after the Spider-Man films, but he's turned it around, mostly thanks to Judd Apatow, who cast him on TV in Freaks & Geeks before he became Harry Osbourn, and set him back on the right road with stoner parts in Knocked Up and Pineapple Express, after which our old pal Gus Van Sant cast him as Harvey's boyfriend in Milk, and all was well with his world. 127 Hours will surely earn Franco his first Oscar nomination. There's a lot of acting going on up on that screen.

Boyle is often characterised as a risk-taker, and there's a lot of truth in it. Slumdog was a risk that paid off. So was 28 Days Later before that. And Sunshine, which didn't pay off quite as handsomely, although I really loved it up until the ludicrous denouement. Trainspotting itself wasn't the sure thing it seemed once the marketing had kicked in, and nobody knew what Shallow Grave would do, or whether there was even an appetite for a Scottish chamber piece. And as much as I disliked it, you have to hand it to him for having a crack at a large-canvas American screwball comedy with A Life Less Ordinary. He's a useful person to have on our team, and although the hype around 127 Hours can seem offputting, and you more you read about it, you more you think you know what it's going to be like, it really has to be seen.

A word about the defining act of the story and the advance squeamishness you are feeling about it (just as I was until this afternoon at the Curzon): it's beyond belief what Ralston did to free himself, and it is the film's money shot, or shots. But that's not to say it's exploitative. If you enjoy the Saw movies – and, after the first one, I categorically do not – you may still be shocked. Not shocked by what you see – as with all the best cinematic gore, it's as much imagined, and felt, and heard, as seen – but shocked to see a sequence of extreme corporeal violence that is actually central to the story. The bloody shocks in Saw are designed to shock and shock only. This one is designed to make you ponder your existence. No, really. Ralston was – and presumably still is, in his DNA – a loner. A true independent spirit. He jumped down canyons alone, with his headphones on, at one with nature and the last great wilderness, but at one. Most of us would prefer not to be on our own for 24 hours, let alone 127, and if trapped as he was, we might not have had the mental tools to get out of it.

I am not an adventurer like he is. Never will be. But nor, I hope, am I selfish, arrogant bastard who ignores his mother's ansaphone messages and takes off without telling a single soul where he's going. But there's even a postscript to all that at the end.

Warning: 127 Hours contains a song by Dido.