Simple and charming. Great fun and the mechanics are really very cleverly developed that work very well together. It is very nice how it loops back to the beginning and you give a whole new dimension to earlier levels with the color shift. Very well done.
One tip about your credits, you should be clear what you used from the artist, so include the name of the asset and what it is (like music). Please implement this properly to prevent any problems with being flagged for insufficient crediting, because that would be a great shame for your awesome work.