It's a masterpiece, plain and simple, a stirring example of the narrative and visceral power of cinema. Was that pretentious enough for you? Get off the couch and go, people.
Technically, the movie is nothing sort of awesome, using watershed visual effects to show you things you've never seen before. Think about that a moment. Filmmakers face an incredibly sophisticated audience that, like some kind of CGI junkie, needs bigger and bigger spectacles to get that kick of excitement to justify $8 tickets and $10 soft drinks. (We suspect that the protracted, eye-popping finale of The Avengers is one reason that movie was such a ridiculous success, but we digress.) But writer-director Alfonso Cuaron and cinematographer Emmanuel Lubezki find multiple ways here to push the envelope. Disintegrating spacecraft coming apart in the soundless vacuum of space, glorious sunrises and sunsets from orbit, beautiful-yet-deadly microgravity flames, out-of-control astronauts spinning in and out of sunlight, Sandra Bullock floating in a space station. Read a little about the movie's years-in-the-making backstory and you'll see what we mean. The filmmakers invented entire new camera rigs and production processes. You may have heard comparisons to the iconic, groundbreaking outer space visuals of 2001: A Space Odyssey. It's no hyperbole. This movie is that good. (Just make sure you see it in 3D and/or in IMAX for the full effect.)
As for the story, it's a cousin of Cast Away, putting a smart-but-inexperienced character into an impossible situation where survival depends on resourcefulness, luck, and a need to toughen up real quick. Stories of survival are our most primal; everyone can relate to a desire to cheat death. So there's a simplicity to the story. We know what Sandra Bullock and George Clooney's characters must do, so it becomes a question of watching them succeed or fail by overcoming obstacles the plot throws in the way. And there are a lot of obstacles. This is one of those "Murphy's Law" movies we love so much - everything that can go wrong will go... and at the worst possible moment. Even better, unlike so many recent would-be blockbusters, Gravity doesn't feel the need to drag everything out over 120+ minutes and cram in multiple loud climaxes and arbitrary, exhausting plot twists. This movie's barely an hour and a half long. That gives the action a lean, sparse quality. There is no fat. It's got, like, momentum.
It's also got something else: narrative ambiguities. This is the sort of extra layer that can transform good movies into great art. We don't want to spoil the movie, but there's more than one way - as you may have heard - to read the movie's last act. There is no right answer. We viewed it one way, then started wondering if maybe we had it wrong. (And it's not one of those annoying European-style open endings where you have no idea what you just saw or where the film just ends abruptly before a resolution like "The Sopranos." This is more of a... fuzzy ending.) Cuaron seems to want his audience to, you know, think. He's designed it that way. Even better, the story's plot is ingeniously linked directly to Bullock's own personal crisis of faith. Screenwriting professors talk a lot about how a character's external struggle should mirror his/her internal struggle. This is a textbook example of how it's done. Admittedly, we didn't catch on to some of these poetic parallels until much later (i.e. Bullock may be sort-of, kind-of suicidal, which is echoed in her situation in the movie, stuck between the earth and the heavens). But that's why the movie is so brilliant, people. It begs repeat viewing to look for more meaning, more connections, more metaphors.
As for the acting, Clooney does what Clooney does best: exude swagger and charm. Bullock has the harder task since she's alone for a good chunk of the movie. The part isn't as showy as Tom Hanks' part in Cast Away if only because this movie has more of an action vibe. It's a lot of "Argh!" and "Oh no!" and "Eeeek!" But she does get a couple of powerful monologues and a showy emotional breakdown moment. An Oscar nomination is a sure thing. Will she win? Not sure. But it's a far more subtle, emotional performance than the showy, rather shrill "look-at-me" one from The Blind Side that got her Best Actress a few years ago.