Don't go in expecting you're gonna get a movie with fleshed out characters or a coherent story. The thing you're gonna get is just a bunch of music videos mashed together.
The way the story is written is how kids from elementary school play make-believe with their friends. (only the friends have magical powers, everyone wants to get a bit of that spotlight, being a bit grotesque sometimes for the fun,...). It seems as if Martinez had a lot of fun with this project and I don't blame her, if I had the chance I would do the same.
My main problem with the movie is that it tackles way too many themes (bullying, transphobia, body image,...) and it ends up being a "we live in a society"-mess wherein only the obvious get stated without saying much in depth about it.
I do praise the movie for the costume design and set design, the colors in this movie had me in awe and that's what you kind of expect if you've seen Martinez previous music videos for her Crybaby album for example.
I would recommend this movie to people who are a big fan of Melanie Martinez and for the people who watch movies solely for the aesthetic.