Fantastic! I liked it :-) It has a very clean and simple aesthetic. The music fits well too.
A few pointers (forgive the possible pun) for improvement areas:
The keyboard and mouse control is a little clunky. Consider making it all touch/mouse. This app could work well on mobile, with a rotation gesture to spin the box.
I want to hear that music track progress further. Unity have some great templates for handling adaptive music in games. I've used this one: