I want to provide a more balanced point of view than the other two reviews here.
The finale was epic and action packed, but it felt... somewhat lacking, and I think I know why: This episode wasn't about Kipo. It couldn't be. In fact, the last three episodes weren't about her.
Kipo's story ended when her friends convinced her to not slaughter the Human Resistance. Her entire character arc was based around her struggle with the world rejecting her beliefs. She believed that everyone deserved a second chance; the world was telling her that most people didn't even deserve a first chance. So, when she decided that she was going to give the Human Resistance a second chance, even after they effectively killed her friends, she resolved that internal struggle. She resolved her character arc.
This is also a heavily character-focused show, and the character that it focuses on the most is Kipo. In fact, the entire show's plot is centered around Kipo's character arc. So, when the final episode rolled around, the central tension of the show was gone. The true climax had already happened. That, I believe, is why the finale, despite wrapping things up in a very satisfying way, felt so anitclimactic.