Tekkon Kinkreet--a title I hope to type as little as possible in the rest of this review--is a strange movie. The whole thing sets out to tell you that it's a little bit strange, and it delivers on that promise.
That said, it's quite good. Just strange.
There are at least two plots in this, and a variety of subplots. The most obvious plot is that of the Cats--Black and White--against the yakuza and the monster they bring in, Mr. Snake. This plot, once you set aside a lot of the urban fantasy elements, is pretty straightforward.
The more interesting plot is the relationship of Black and White and Black's battle against his inner demons. This plot is largely played out in the Black's subconcious. I think. In fairly classic tradition for anime as they enter their conclusion, it gets a little surreal in the end, and what's going on and how becomes less than entirely clear. But I grew up on Evangelion--surreality I can handle. In Tekkon Kinkreet, at least, I don't have to watch a naked teenage girl melt into goo while giggling. This is a net win.
There's a legitimate complaint to be said about the narrative jerking around a bit, but we're talking about an anime that is operating on a fairly symbolic level, so I'm not sure those complaints hold too much water. In any event, they didn't interrupt my train of thought. But then, I only watch these things in 20 minute increments. If you sit down and watch it properly, you may hate it. Which is entirely your problem.
I have to preface this by saying I love reductionist art. The character designs that people have complained about delighted me, because I enjoyed seeing the level of differentiation the characters had even though each were composed of just a few pen strokes. It upped the surrealism of the movie, which I think is the only way you can swallow everything, so I call it a win.
The backgrounds and scenery were equally fantastic, and detailed to a level that really called out the contrast between the city and the people in it.
Lastly, the actual animation was slick and pretty--there are some delightful to watch moments when the Cats are navigating the city or engaging in their chief recreation of purposeful violence.
The sound was good. I didn't notice the music much. Moving on...
The characters in Tekkon Kinkreet are split between the well developed and the archetypical. Black and White are well developed, beginning as a pair of violent street kids and showing real depth in their relationship. Black experiences some genuine evolution of the course of the movie, which is good, since that seems to be the actual plotline. White, while seemingly unchanging, still grows in depth over time.
The stand out character is actually a yakuza, Kimura, who over the course of his personal subplot goes from a petty gangster like any other to a sympathetic character trying to build a life for his family.
The other characters are interesting, but as I said fall back on archetypes. Mysterious villain, wise kindly old man, hard-edged cop, and so on. I can forgive this because there was less than two hours to develop all the characters. Hopefully you're a reasonable minded individual and can forgive this as well.
I liked it. Surreal, but no melting people. I may even watch it again someday, so I can decide whether people were literally flying around or there was some metaphor I was missing.