Steven Universe as a show was great. The film is a brilliant homage to the show and is a good bridge to the Future epilogue mini-series.

Having Spinel pop up out of nowhere with no backstory was a little strange, but it was made up by the fact that the main characters didn't know who she was either. It really put the audience in the same shoes as the Crystal Gems. Her character arc was nice to see, even in such a short amount of time.