Loved every part of it. My one nitpick is that the final act included a bunch of robot battles.
I understand that's probably how the book went, but I kinda hate how every modern film no matter how quiet and emotional has to inevitably have its marvel action ending.
But it didn't ruin the movie or anything, so I'd still give it an A. Without a doubt the best original animation in years. At least that's come out of Disney, Pixar, DreamWorks or illumination. Encanto might still be better though.