Finally saw this, and I will say these positives:

-My three year old son loved it and I love that my son is getting into Nintendo stuff as a huge Nintendo fanboy myself.

-Everything about Bowser was great in this. He is by far the highlight of the movie and if everything matched him this would have been a good movie

-I liked the brother dynamic of this movie. More of a focus on that kinda like what Frozen did for sisterly love would have made this a good film.

-The animation is phenomenal

That is all the good I have to say

C+