I watched it in the theater with my 9-yr old daughter. She LOVED it! She was so excited when she started to put together that some creatures were like white blood cells, etc. She said, "I LOVE science!" and already wants to see it again.
I thought the creatures and scenery were well-done, there were a few funny jokes, and I liked the representation, which was just people being people without a huge focus on their identities.
I also know and enjoyed telling my daughter about Turtle Island and appreciate the ecological messages and the demonstration of generational change. It wasn't my favorite animated movie, but it's a solid 4 stars for sure (my daughter would say 5).