The art is very distinctive! I like the long flowing hair of the character.
The purpose of lighting balls which collected along on the way is not clear enough, maybe it can show how many lighting balls was collected and representing player's score?
I like to write "end" directly in the background when player reach the end, but since the character can still be manipulated, it doesn't have the feeling of ending the game.
The color of the background and the slowly moving mountain view are great!