Could have been a masterpiece
The biggest issue I had with this was that it couldn't let itself have a serious moment. Several times it had a beautiful thing going but ruined it with silly comedy. I understand that this is a kid's movie, but the first two weren't as cheesy with their humor.
Also, Kai seemed like he wasn't as fleshed out as the other villains.
I wish Mads has stayed on for it, but Simmons did well.