Seriously, giant spoilers, I'm not kidding. Turn back nowwwwww.
So there's that first scene, the one you see in the trailer where Clive Owen buys his coffee and suddenly a storefront blows up behind him. Right before we cut to another scene, there's a woman staggering out, screaming, and she's got no left arm. It's been blown off. Now, it went by so fast that I'm not sure, but I think she may have been holding the arm in her other hand. This is the movie telling you what you can expect: shit is going to happen when you least expect it, and the gore might stay in the background, but it's going to be there, and it's going to be realistic, and it's going to be bad. And then, I don't know how far in exactly, but I'd guess maybe 30 minutes in: Julianne Moore dies, in pretty much the most sudden and shocking way possible. This movie is telling you at this point that absolutely no one is safe, and in fact, I turned to one of the friends I was with and muttered, "Oh, shit. Everyone's gonna die, aren't they?" The movie is telling you that life is short and senseless and unfair, even as it dangles this one thread of hope, and it's pretty much going to keep telling you this, and here's why that's brilliant from a filmmaking point of view: you spend every single second waiting for the other shoe to drop. You figure that whatever the worst that could happen at that particular moment is, that's what's going to happen. And a good bit of the time? It does. There was a point where I was actually like, "Yay! [Someone]'s going to use the suicide kit! Thank God." This is also the kind of movie where, two minutes later, you find yourself mentally shrieking, "Fuck! Why didn't you use the suicide kit! I'm sure there was enough for both of you!" Hell, this is the kind of movie where suicide kits are advertised on TV like allergy medications ("You Decide When It's Time"); you half expect the ad to end with a soothing "Ask your doctor!" My point is, after Julianne Moore took a bullet in the throat, we spent the rest of the movie expecting bombs to go off during any momentary lull and whoever was currently onscreen to get shot in the head in the middle of his next sentence. Cuarón didn't even have to build up any kind of suspense--we did all of that for him. The camera just charges through the movie like a war correspondent; there's a fairly long sequence following Owen in a dash from ruin to ruin where there's three drops of blood on the lens for the whole scene. And while there's some really beautiful framing in a scene where Jasper talks about Theo's son--and apparently some "unprecedented" camerawork in the car/death scene, the camera mostly just watches or follows, dragging you with it. Most of the horrors happen in the background--keep an eye out for some Abu Ghraib-esque imagery when Miriam's taken away--which ratchets the tension up even higher; you feel like you're being assaulted from all sides, and you never know when any of those horrors are going to charge in front and center.
At the same time, there's a surprising amount of humor in the movie. As awful as the first car chase is, the second--possibly the slowest car chase ever filmed--is hilarious. And you will never hear "Pull my finger" quite the same way again, I promise you that.
Two reactions I want to note, for some reason:
1) Clive Owen is trying to get away from a minor character who is both 1) heavily armed and 2) deeply pissed off, and takes him out with a brick to the face. Like, a really graphic, squelchy brick. We hear about three rows' worth of guys in the front of the theater all simultaneously wail "OHHHHHHHHHH." Seriously, they may have all been together. For some reason, I think that was the most visceral reaction from the audience in the entire movie, and it wasn't anywhere near the most graphic or harrowing.
2) We were sitting through the credits trying to process what we'd just seen (well, technically, I was trying to screw my glasses back together, as they decided to fall apart at precisely that second), and a middle-aged couple passes us going down the stairs. The woman, who has reddish grandma hair (you know the style I'm talking about) stops, looks at us, and says "Did you like that?" We sort of stare at her, and she laughs in this Yeah, me neither way, and kind of swats her hand and says, "Nahhhh." Guys? It's not the kind of movie you "like." It's a great movie. But you're not gonna want any popcorn, if you get what I'm saying.
Also, I can’t get rid of this nagging feeling that “children of men” is a famous phrase or a quotation of some sort, but I can’t place it, and searches aren’t turning anything up. Anyone? ETA: Ahhhh, Psalm 90. There we go. ETA: Okay, folks are coming up with multiple Biblical references. Interesting.