Okay, I'm going to be honest. I cried through, like, all of this movie. It's about Jack Frost, and other contemporary child-mythology creatures -- Santa, the Tooth Fairy, the Sandman, and the Easter Bunny. They are the Guardians, and they protect the world's children. Basically, they work to increase awesome and fight worldsuck.
I wanted to see Rise of the Guardians ever since I found out that it's not the next installment of the Guardians of Ga'Hoole movies. Specifically, because I found that out in io9's interview with Guillermo del Toro about the movie:
What's the biggest mistake people make in telling stories about children, or for children?
Well, I think that one of the things is to actually try and create a sense of darkness in the tale. A lot of people just make this sanitized super happy-go-lucky, "bright sunshine and clouds" type of childhood movies. And you really need an element of the dark in it.
The movie opens 300 years ago, with Jack Frost being born at the bottom of a lake, and the moon telling him who he is.
I mean, like, his name. He doesn't tell him anything else. He gets a name, and finds a magic stick, and he's basically left to figure things out from there.
Spoilers below the fold.
The main villain of this movie is Pitch Black, who is the boogeyman -- and the main enemy of the guardians. Jack is selected to be a guardian at the start of the movie, when they find out that Pitch is coming back, but through most of the plot he's kind of reluctant. Pitch calls him a "Neutral party" -- because they both go unacknowledged by children around the world. Whatever these people are, they are powerless and alone without the belief of children.
Pitch is a painful villain to watch. He can't win. It would be the worst thing in the world for him to win, because for him to be believed in, people have to be miserable and terrified.
But losing means he has to be alone, and the film makes you feel that. Pitch is miserable. He's unloved, uncared for, afraid, and he's going to be around forever -- with the handful of people who have anything in common with him sworn to fight him back down into the underworld if he ever makes a peep.
Jack's almost that badly set up -- he doesn't know why he exists. Unlike the rest of the Guardians, he only remembers becoming Jack Frost, it's not till near the end of the movie that (SUPER SPOILER DON'T READ UNTIL YOU'VE SEEN THE MOVIE) he finds out he used to be a human boy, with a family, and he died saving his sister's life from cracking ice.
Jack doesn't remember that. For three hundred years, he didn't know why he existed, what he was for, why nobody, anywhere, apart from the Guardians (one of whom doesn't even like him) can see him or knows he exists.
Everything bad or sad in this movie is excruciatingly tragic. Everything good in this movie is miraculous. It makes sense, for a children's movie -- with as little experience as children have, most things do reach to the very edges of their ability to feel. To quote Randall Munroe of xkcd, "Our brains have just one scale, and we resize our experiences to fit."