Dax vs GK For a first this is pretty nice! I also like your sounds, it seems like you took some time to make sure your SFX are good. The sounds on my first animation were pretty crappy xD
A suggestion from me is to make the background feel more alive. The most simple way to do this is by making the clouds in the background slowly drift as they fight. And perhaps put some trees and stuff unless you purposely wanted the place to feel barren. Which is fine.
