Gravity is a surprisingly short movie, until you start to think about how little plot it's got and how they'd have ruined it if they had to spin it out a bit longer. Cuaron and his team decided to keep it short and simple and get the short and simple thing exactly right. Better call, not least because if they'd run it up to the more usual two hour plus mark of a big budget movie, I'd probably have had a heart attack from the accumulated roller coaster shock.
For all the simplicity of the plot, there's a lot to think about in Gravity. For one thing, it hammers home just how precarious humanity's little toehold in space is. Everything is ridiculously difficult in space, and it only takes one small thing - any of millions of small things - to go wrong and kill you. For another thing, it gets you thinking about the fragility of things we've started to take for granted. The driver of the whole plot is that the Russians screw up destroying an obsolete satellite, scattering debris throughout its orbit. The debris knocks out more satellites, which splinter and knock out more, till a cascade of high speed shrapnel wipes out everything in its path, including the International Space Station and the Shuttle which George Clooney and Sandra Bullock are space-walking around. Clooney's Matt Kowalski comments drily "There goes half of America's Facebook." And most of its TV and phone networks, not to mention the internet and satnav.
Don't shrug. The internet and satnav now play nearly as big a role in making sure there's food in your supermarkets as farmers do. No internet, no inventory and ordering systems. A clean sweep through the satellites holding that stuff together; civilisation teeters. It's an old truism that no culture is more then four missed meals from anarchy.
Cuaron doesn't waste any time on the mere destruction of our modern way of life; he's got something much more immediate to sort out. Are Kowalski and Sandra Bullock's Ryan ("my father wanted a boy") Stone going to make it back to earth as anything more than glowing debris? As I keep saying, keep your action personal and immediate; none of us can really imagine the end of the world, but we can all imagine the end of our own world. Or, to quote Ryan Stone again, we all know we're going to die, but it's different when you know it's today.
Cuaron's calling card among people who care about movies is this famous scene from Children of Men. If you know anything about his work, you know it was done in a single take, using one of the most preposterously complicated camera rigs of all time. But when you're watching it, you're not thinking at all how complicated the shot must have been or how unlike normal editing and cutting it is; you're just immersed in the moment, drawn in and lulled until the action starts to become terrifying. Everyone's sat in a car talking backing and forth, and Cuaron found a way to make you feel that familiarity, that sense of being among the people in the car, so that when things start to go horribly wrong, it feels - as they always used to say about movies - as though you were there. Cuaron knows how to make a scene all about what's happening, and what's going to happen next.
Gravity was almost entirely CGI; it has only two actors and all the space scenes were - of course - done in computers, with just the actors' faces inserted by magic into the fake surrounds. But even when the action is inside the shattered space station or limping capsules, much of what you're seeing is CGI and painstaking choreography of actors jumping and swimming through things which they couldn't even see. The brilliance of Cuaron's work - his direction and his script - is that you never even think about how it's done; you're too busy hyperventilating as you try to figure out what's happening to the people and what might happen to them next. The vision of earth orbit and all the things flying around in it is perfect (probably technically wrong in all sorts of ways, but apparently flawless), but it's background to what really matters; people and what they're doing to survive.
It's a superb piece of work at a purely technical level, but it works as a movie because it's a wonderful piece of work at a human level. Yes, Clooney and Bullock are good actors, but in something as fake as an all-CGI movie, even good actors need a great director, and it's astonishing that someone could do something so technical and still have what it takes to get the best out of actors too. Apparently James Cameron is a huge admirer of the movie (and the computers to make it probably owe their existence to the grand loon of Avatar) but there's a telling little story about the difference between Cameron and Cuaron. Cameron's famous for pushing his actors to the point of near death and not caring very much, and that indifference to people tends to show in the results. Cuaron at one point had to put Bullock into a situation where she had to hold her breath through the whole take. And he held his breath with her, to make sure that he didn't push her beyond what was manageable for her.