Pikachu is Tim's father who was trying to save Mewtwo. The Villain wants to turn people into pokemon. There's like two pokemon battles in the entire movie. They swear three whole times.

The portrayal of Tim's depression is actually kind of painful to watch and not kid-friendly. He just stops feeling.
You have to have at least a decent knowledge of pokemon to understand the film but once you have that knowledge the film might come across as massively cheap in comparison to what you could have had