I have a few problems... but overall the movie is outstanding.

Rating: 7/10 (18 February 2018)

Before you start reading or vote unhelpful, let me tell you some things: first of all that I am mexican and second of all that yes, it is a children movie... That deals with death, cheating, murder, treason and kidnapping; so any criticism I make is going to be like of any other movie. The "this is a movie for children OMG!!1!" defense is pathetic and you should be ashamed of using it in this movie.
Lets start with the title. We found until 20 minutes into the film that Coco is the great grandmother, that has importance until the last 15 minutes. Why calling your movie after an element so unimportant until too god damn late? That would be like calling Se7en 'the box' or Wall-e 'Angry Captain'. Why not "Miguel's tale" or "Music in the heart" or "land beyond death" or some other title?
First of all: The animation and the music are really sweet. Both elements are beyond the normal animation. The music is actually chilling, so adequate, extremely beautiful. My only criticism is the dumb dog that is there as a comic relief in an already funny movie, Why does it exist is beyond me. You could have kicked it out and nothing would have been lost.
The voice acting is outstanding. I loved it and it actually expresses emotion. They deserve a raise.
The plot is solid... although I have a question that is almost nitpicking: Why in the name of everything holy would his great great grandmother doesn't tell him that De La Cruz is not his Great great grandfather from the beggining? You know... What any person in the universe would have done after hearing "I am going to find my familiar, de La Cruz!" and knowing he is not your family! I know this would have made the movie an hour shorter, but at least it would not have put your Great great grandson in danger... something anybody would have done. And how did the family made everyone forget about De La Cruz in one measly year? That would be like finding out The beatles stole all of their music and make people forget about them in a year.
It is an good movie. I would watch it again.