Moonrise - student project

See the video for my little animation here.

I know essentailly nothing about design or how to use Phototshop or Illustrator, so I tried to keep this very very simple. 

I want to change the color of the moon as it moves, but can't figure that out yet. Also want to animate the stars, but they are currently all stuck on one layer so I can't do anything with them. I don't know why the edge of the hills looks so pixellated, but if anyone has a suggestion on how to fix that, I'd be happy to know.

Any feedback is welcome!