Edit: I'm going to keep my original review here for posterity or some shit, because I wanted to like the movie. It had potential. But as it stewed in my headbones, I really grew to resent ever paying so much to see it, and really don't recommend it to anyone anymore.
I went to the midnight showing last night. Pretty bummed that almost no one responded to my request on facebook that people join me, but more people did show up, and people I thought wouldn't make it did :).
I paid $13.50 a ticket because Boyfriend likes 3D and I wanted to treat him, because he so rarely gets to go to the movies with me on opening night. But the film wasn't really made well for 3D. There were a few nicely rendered scenes, and any other 3D in it was pretty subtle, but all-in-all, don't bother.
POSSIBLE SPOILERS, but I'm not going to cut for spoilers, because I'm pretty sure most people who'd go to see this is a fan of the show. Plus, most of these scenes were shown in part in the trailers.
The film managed to stay pretty faithful to the show. The mining town (with the unnamed Haru), the Blue Spirit scene (and after, in Zuko's room), the final scene of Princess Yue, those fucking bad-ass Fire Nation ships!... People I was with complained that such-and-such a scene wasn't as quick as in the show, to which I replied (every damn time), "They shortened it! They're not going to go through every damn episode in full, jerk-wad!" There were a few scenes which were terrible, like the scene in Kyoshi. Although this scene was a relatively accurate portrayal of a scene in the show, it was not supposed to be set in Kyoshi, and that bugged me.
It also bugged me that, although they used the proper Japanese pronunciation of names, they did not say their names as they did in the show. Sokka (pronounced Sah-kah in the show) was pronounced Soh-kah. Aang (pronounced Ang in the show) is pronounced Ah-ng. Iroh (ay-roh or eye-roh) is ee-roh. Agni Kai (Fire Nation duels / fighting tournaments) was pronounced Agni Ki (kee).
The last thing that bothered me was the casting (not all of it, though). I didn't care that they switched skin-colours around so that Katara and Sokka are white (in a village of orientals, though? Way to go) and Zuko, and the rest of the Fire Nation, is Indian (although, even though he looks much older than Zuko is, I thought Dev Patel was a good pick. He sounds a lot like Zuko- but then, the rest of the Fire Nation just doesn't fit the bill as Indian. Iroh I really liked. And I won't be sure about Azula until the next film).
I liked Jackson Rathbone as Sokka, but his character was written half-wrong. I say half, because Sokka can be the serious, caring big brother in the show, but in the film, they completely took away his funny side. He was the comic relief sort-of-a-jack-ass guy, and they didn't portray that a bit.
And Aang! Where's the light-hearted little boy who sneezes himself ten feet in the air and goes penguin-sledding? This kid, terrible actor, by the way, didn't smile once. His voice was dark, and sounded like he was reading cue cards.
And I was wrong, there's one more thing that bothers me. The bending. It played out like video game moves: up, up, down, down, B, A, Start. They did all these elaborate moves, and only on the final move did anything happen. It would have been nice if, when they began their bending moves, there was a sort of stirring going on in the element that builds up to the big hurrah. Most of the time it just looked like they were dancing and doing tai-chi (which yes, that's what it looks like, but if there was something going on with their elements as they were moving, it wouldn't look so... boring).
Overall, it was a good movie. Not a great movie. But I'll still go see the other two films (chapter Earth, followed by Fire) on their opening nights. I like going to things like these on opening nights.
The next film (should it be made- there's no sign of it on IMDB, but Shamalamadingdong is working on it) will star Azula and her awesome mates, as well as Toph, and maybe Jet, and whoever else...