Let me just preface my review by saying that I really do love this anime; I feel it's one of the most solidly unique worlds built in many seasons.
That being said, it's not actually all that well-done.
Story (6):
The plot seemed to drudge on far too slow for a series with this rich a history; 13 episodes in, I still have very little information on the world, and they don't ever explain how they went from being able to build a giant wall to being unable to repair a small break in the wall. Did all your masons just jump off the wall when they finished?
Art (4):
The art is horribly sub-par. The entire show is a 30-minute clip show. They pan across stills like it's some documentary on historically important toilets, but I really don't think anyone is fooled by it. The character art is a tad awkward, with the outlines being far too bold. The titans look like giant neckbeards (I swear it's like looking at a group of my friends naked), and could probably use some work on the texturing; the mouths are intentionally part of the effect of the titans, so I can't really blame them for leaving that in, as weird as it looks. The background art is beautiful but with content like this, I'm not surprised it looks beautiful. The intro has a terrible portion where they seem to have accidentally lowered the contrast and brightness; every time it shows, I think my backlight's gone wonky.
Sound (8):
The opening sequence is is arguably the best this season, and really gets me pumped to watch the show; a large part of why I'm still watching the series is because of it. The soundtrack as a whole is pretty good, but it has to be, since the animation is so bad. The voice acting is okay, but sometimes I feel they're just screaming into their mics when they should be putting actual emotion (besides yelling) into it. It's disappointing, really.
Characters (6):
They've barely added given any backstory to the characters thus far. Mikasa is a badass, we get that, thank you; move along, please. The side characters are essentially left with vague wishy-washy backstories like "yeah she likes potatoes and came from the north" with absolutely no idea what makes "the north" important or unique. And Eren is a huge deus ex machina with odd timeline-breaking flashbacks that make absolutely no sense.
Enjoyment (9):
I love this anime to death. I ignore all the bad qualities, and continue watching it anyways, because above all else, they built up this amazing world with great history and awesome scenery. There's depth to this series, more than I can even imagine right now.
Overall (10):
Honestly, disastrously bad; if an anime can be ruined by flimsy characters, poor art, or screamy voice acting, this show is not for you. If you can ignore these aspects, you're in for one hell of a world. I haven't loved a flimsy anime this much since Sword Art Online.