My absolute most favorite thing for me -- the thing that totally made the movie -- was the giant forest animals and the Forest God.

Morrow, the giant white wolf, is one of the last remaining animals that are descended from the Gods. She can speak in a human voice and has two tails ( possibly a reference to the Japanese belief in multiple tailed fox spirits known as Kitsunes. ) Likewise the Forest God is beautiful and very impressive, and turns into a giant blob with stars in it, so...
Yeah. Those were my favorite things.

Also, I think that forgiveness is the driving force behind the movie. It's all about learning to live together because when we fight, no one really wins. Understanding and forgiveness are the main themes in the movie and very important. The environmentalism aspects are there, but for me they come in second.