Lovely! Tons of charm. The music and art were really pleasant. The art in particular was really excellent. Took me about 5 minutes to beat it, I'd love to see it fleshed out more, the gameplay was simple but engaging. It was pretty intuitive too, but not so much that it was a cinch.
Two programming faults I found: If you hold the jump button you continually jump every time you come in contact with the ground, and if you hold left or right against a wall while falling you get suspended in mid air.