Lovely graphics and nice settings. Unfortunately the unicorn is hard to control which limits the fun. Also it is hard to climb the clouds when you vanish within them.
As a start I'd probably make the unicorn a bit faster (and the enemies too so they can keep up). Since the world is rather empty it gets tedious running from one collectible to the next. Also a small circle underneath the player would be nice so that I can gauge better where I will land.