There's hardly anything I would improve about this film. The visuals, concepts, soundtrack, characters, pace, humour and animation are all some of the best I've ever seen in any film; I was worried the hype would ruin it for me, as it always does, but not even the group of kids in the theatre who wouldn't stop loudly talking could ruin it for me. It is visually engaging and beautiful in every scene, not to mention with an incredibly unique art style, and is honestly something other animated movies should have to look up to for a long time. The only real issue I can think of is the flashing lights, which really alienates any epileptic audience, but even then it's done so in a beautiful and artful way.