This movie doesn't deliver emotionally
I think the biggest problem with this movie is that nothing absolutely heart-wrenching happened. Compared to Mind Game, (I know, different director, but its my bases for movies of this type) which really delivered a hard message about life, love, and just making the best of things, "Tekkon" just doesn't deliver any theme outside of the regular.
Throughout the entire movie, I kept expecting something to happen where Black would sacrifice himself for White, or something along the lines that would nigh-bring me to tears. However, the only scene that got close was when White got stabbed, but we're quickly told in the very next scene that he's ok.
This movie failed (for me, obviously not for everyone) to evoke that strong emotional reaction that makes a good film. The reason I said it should be terribly sad is because that's all that this movie could really do. It needed one emotional that would really make me go "wow, this movie was worth it for that," (which in this case was the animation, but that's not what I'm talking about) but it just never happened.
I apologize if my thoughts seem disjoint, I'm not thinking very clearly right now :/