Too bad could've been great
I thought this animation was going to be really good, but as soon as I saw the opening story sequence I was disappointed. You seem to be trying to achieve a skill level similar to the better animators on NG, but you're having some trouble with it. I would suggest not using the paintbrush tool so much. I would also suggest working on your use of gradients, they need to have much softer transitions instead of just solid colors to solid black. You can edit the gradients levels by using the color mixer on the left hand toolbar. Umm besides that, I'm sure you've already heard the other criticism about sound and what-not. Oh one more thing, spend a lot more time on the backgrounds, they were ugly.