I think "Gravity" must be the first ever instance of a screensaver being re-calibrated and re-packaged as a cinematic experience. It's all well and good demonstrating what the latest and greatest in special effects is capable of, but of what use is it without a scrap of substance to back it up? Rebellious though it may sound, films such as "Gravity" are neither enhancing nor prolonging cinema, in fact they are killing it and if there is a genuine zeitgeist amongst audiences that this is the future then cinema has very little future to look forward to.

"Gravity" opens with a blank screen followed by a series of ultimately pointless statistics pertaining to the nature of the space vacuum. Its temperatures, we're told, "fluctuate between minus 148 and positive 258". "Sound" it says "is unable travel" So what? To what is this any reference? Where is this relevant later on? We then begin with a startling composition of the lower hemisphere of Earth from outer space - our eyes are distracted by the land mass to the left of the frame as it slowly comes to form due to the Earth's rotating, failing to notice the object which sails into our eye-line from the hard right of the screen.

Lo-and-behold, it is the Hubble Telescope, and we meet our characters in the midst of spacewalking their way to upgrading said telescope. One of them is Matt Kowalski, played by George Clooney - a Texan stereotype with a brash attitude; a love of old cars, country music and a backstory that saw his ex-wife leave him 20 years ago. His opposite number is Sandra Bullock's Ryan Stone, a comparative rookie; a woman who doesn't really belong in space, whose past tragedy is her young daughter's recent death and who seems to be perpetually nervous when compared to Kowalski's bombing around confidently on a jetpack.

Disaster strikes when, out of nowhere, debris from an exploded satellite that has collided with a second satellite sends a glut of space junk the way of our leads. There is some clumsy propaganda about it being the fault of the Russian Federation, but this all acts as the catalyst for Cuarón's feature to turn into a mad dash for the sanctuary of a working spaceship, and then home, as the methodical Kowalski and the unhinged rookie Stone grapple with both one another and the elements.

Understanding why "Gravity" has done so well and received a lot of praise is at once both baffling and painstakingly obvious. It is an incredibly simplistic film - people take to it because of its linear nature; easy causality and the not having to follow any kind of narrative. Much in the same way crowds took to James Cameron's "Avatar" for similar reasons, the special effects play their role in hooking people in. It is also the case a character you expect to be around by the end is removed from the piece very early on, which I think has stunned people into thinking they've seen something of greater substance because they've not previously seen it happen.

The film essentially consists of a string of action set pieces told from the constrained perspective of those involved as they dodge a series of life threatening near-misses. Some of these are born out of the chance event of the space debris flying their way; others rely on the more convoluted occurrence of an onboard fire. Limited air supply also acts as a rudimentary source of drama. These set pieces might well happen in any order and be of any length of time. There is a heavy reliance on imagery and visuals; a complete lack of story and an all but total lack of complexity.

The film's apparent core strength, that of a strong female lead in Bullock's character, raises further questions. She has short hair; a boy's name (Ryan - something the film bothers to bring to our attention when Kowalski mentions it) and gets to fulfill the role of an astronaut - a job otherwise synonymous with men. She is androgynous in this respect, but it is Alan Evans writing for 'The Guardian' who points out that she needs either chance or other men to rescue her from every situation - rarely does she use her own ingenuity and, indeed, spends most of the film a gibbering wreck. The over-not to mention needless-use of shots of her dressed in her underwear when not in a space-suit is equally perplexing.

I accept, on the one hand, the majesty of the special effects and their ability to bring planet Earth to life as this rotating orb of blue ocean; white cloud cover and green land mass, as we float around in the space vacuum. In terms of characterisation, Cuarón seems to want to tell a story about somebody dealing with grief; discovering that life carries on and coming to want to grab it by the horns again, and this is admirable - but it gets lost. I note with deference as to how small and insignificant the film seems to want to tell us we really are in the grand scheme of things: Earth; Space; the Universe, etc.

And yet, the film is piecemeal and ultimately a little underwhelming - dare I say even dull? People have mistaken well-worn disaster movie genre tropes for top-level art because it had a shiny surface, or because they felt like they were able to reach out and touch it, or something. If enough people get it into their heads that this is the future of film-making or what constitutes a cinematic experience, then there will not be much of a future to look forward to.