Inception, Christopher Nolan, 148 mins (12A)

Without doubt, Christopher Nolan’s Inception features some of the dizziest images ever seen in a Hollywood film – cliffs made of crumbling towers, Paris folded in half, zero-gravity fights in hotel corridors.

Inception’s setting is the universe of dream – yet, outré though it is, Nolan’s creation isn’t nearly as dreamy as it promises. Save yourself a few bob: before you go to bed, watch the trailer online, eat some strong blue cheese, and let your slumbering mind write its own script for Inception. It’ll be more involving than this over-crammed, self-indulgent folly.

You can’t fault writer-director Nolan – the prodigy behind Memento and two of the Batman films – on audacity. You don’t often see a Hollywood film that blends at least two genres, a left-field premise, labyrinthine plot, and an eye-popping budget (reputedly $200m). Inception also contains a staggering amount of exposition, breathlessly gabbled by the cast between action sequences. So, as breathlessly as I can, let me précis...

Industrial spy Dom Cobb (Leonardo DiCaprio) specialises in extracting people’s secrets by entering their dreams. He believes that you can also plant thoughts in your victims’ minds: a technique called “inception”. Japanese businessman Saito (Ken Watanabe) hires Cobb to do just this to Robert Fischer (Cillian Murphy), heir to a dying tycoon. Now, you need to know several things here: a) Cobb and his team operate by having themselves and their target drugged up and wired together, so that they’re simultaneously asleep and sharing the same dream; b) these dreams, scrupulously designed by Cobb’s people, don’t mess around with airy-fairy Lewis Carroll nonsense, but usually resemble the paciest moments from the 007 canon; and, c) most importantly, dreams contain other dreams, so that without warning, the entire cast will nod off into another reverie (hence the bizarre sight of a car chase in which nearly all the characters snooze through the action). All this is a hefty dose of background info to swallow, and I haven’t even mentioned such key concepts as the “kick”, the “totem” and something called “Mr Charles” – not a person, but an unfathomably devious tactic which I couldn’t begin to explain.

Nolan unashamedly takes his lead from The Matrix, with its idea that consciousness, like cinema, is a form of shared hallucination. His truly novel achievement here is that he has devised a form of action movie in which anything can happen, and several anythings can happen simultaneously.

The film’s cleverest device is the structure of dreams within dreams, stacked on multiple levels; in Nolan’s theory of the mind, the unconscious is structured like a computer game. If you walked into Inception midway, you’d see it cut between the same characters in a car chase, an avalanche, a lost city, and halfway up a lift shaft – and none of it would make any sense whatsoever.

Now that, as $200m blockbusters go, is what I call avant-garde.

The tricksy logic, which explains it all, is such that Nolan can run several streams of action simultaneously – and at different speeds. Thus, the ski action happens at full tilt while Joseph Gordon-Levitt floats in mid-air in a hotel while a bus plummets off a bridge in hyyy-per-sloooow mooootion. Meanwhile, the characters are, in reality (or should that be: "reality"?), fast asleep on a 10-hour plane journey: Inception is its own in-flight movie.

As we know from his ingenious backwards narrative Memento, Nolan has a genius for logistics. Doesn't he just know it: his characters are constantly pointing out the devilish intricacy of their enterprise. What Nolan lacks is any sense of character – which shouldn't matter, given that Cobb's team are essentially impersonal functions, much like the personnel of the original TV series Mission: Impossible.

But the film's imaginative freefall is ruinously anchored to a bogus sense of deep feeling. Fischer has serious issues with his dad, which resolve themselves in a sentimental revelation of monumental bathos, while Cobb is tormented by memories of his dead wife (Marion Cotillard).

DiCaprio – who looks as if he might wake up at any moment and realise he's still locked up on Shutter Island – scowls sullenly through the more melodramatic moments. And the film has a staggeringly literal conception of psychic truth. In dreams, people's deepest secrets are invariably contained within safes, or in the case of Fischer's relationship with his father, a heavily guarded complex – complex, geddit?

The CGI work, and Wally Pfister's photography, are stunning: there's much play with mirrors and Escher staircases that unfold extra levels of trompe l'oeils. In an extraordinary sequence, Cobb and his architecture consultant Ariadne (ouch), played by Ellen Page, rearrange Paris, folding the city like origami paper. The two also watch calmly as Paris explodes around them, in a scene resembling the cleverest, glossiest sports car advert you've even seen, but which in a narrative film sticks out as gratuitous show-offery.

Yes, Inception is ingenious, visually dazzling, fiendishly executed – but it's grindingly overburdened with action and a Byzantine structure. The problem, I think, is that Nolan aspires to the levels of complexity offered by such TV series as Lost, Heroes and Prison Break – but what's possible in a 13-episode TV series is simply indigestible in a single 148-minute film.

Like The Matrix, Inception offers a self-conscious allegory of digital cinema as a technology of dream: when Cobb offers Ariadne "the chance to build cathedrals and cities, things that never existed," he's invoking a CGI utopia. Yet Inception is without a shred of the actual strangeness, fluidity and intensity of sleeping thought. Dream, as seen here, is controlled, designed, pre-programmed, policed. Inception is not a hymn to the imagination so much as a militant oppression of it – a film that reduces dream to the mundane logic of the action movie.

Next Week:

Jonathan Romney witnesses the marriage of gene-splicing and genre-splicing in a new sci-fi horror story from director Vincenzo Natali