Um, story wise I think they did a great job. The underlying story idea seems rather basic to me "some monster/alien/enemy is attacking human kind and they have to fight back and save the world". I find it a bit cliche (mind you I'm doing the same thing in a story I'm writing... heh...). But they way the story is presented just... works. Even though it's a simple idea, they layer things on top and it comes out so wonderful that you can't help but love it, that is, unless you don't like that sort of thing, which is fine too.
Art! Ohmygosh! It's fabulous! I've watched other anime... well, only a few, but the animation is very smooth in SnK. The way they draw the characters looks prety acurate to me, but you are free to think for yourself.
I recall reading that some people are put-off by the black outline around the characters, but I honestly didn't notice it until they said something. I guess that sort of thing doesn't bother me.
The only thing I don't like is that there are a lot of still images used. I wouldn't mind so much if it was only a few, but sometimes people talk over pictures that move slightly across the screen. Geh, I'm not sure how to explain properly.... It's like a slide show sort of, as if they were too lazy to animate what's in the image or something.
Eh.. the sound is pretty good, however it's not something I really think about. I don't even know how to review it.
I was really pleased with the characters in SnK. They all seem to have individual personalities that work perfectly for them. I'm also happy that there aren't any stupidly cliche busty girls or overly muscular boys. It just seems that everyone has a figure appropriate to their personailty and the training/work they do.
Mikasa.... as much as I like her I don't. She just seems crazy overpowered and even though that's pretty cool, it seems a bit too much. If she just rushes in and saves everyone then how can we see them grow? Those times when she doesn't rush in are great though, as you can watch other people fix their own problems in interesting ways.
Eren is my favorite character by far (because I always fall for the lead male... sigh). Mind you, when they were training to use the 3D manuver gear, I would have prefered if he struggled a bit more, and not just because of faulty equiptment. If everything is easy then you can't watch them struggle to grow! *pouts* But whatever, at least he isn't as super perfect as Mikasa.
I absolutly love this anime! And, I'm ashamed to say, so much that I went back on my promise not to read the manga until the anime was over and caved in. No spoilers though!
Everything about it screams "watch me! you'll love me!" and I do. It makes you want to know how everything works out, how problems are solved and if they will all survive.
Over all I give it a 10/10 just because it has me hooked completely. Even though there are flaws I'm willing to over look them because they rest is so compelling.
Just watch Shingeki no Kyojin for yourself and see what you like about it. Good luck and enjoy :D
