I think it is very creative, and a unique idea. I am not sure how much puzzle you can get out of it. By the third, I did use the hints, and felt like I needed them all, and felt frustrated with the cluster of balls. Like an "How am I supposed to know that?" feeling.
There is a bug with the buttons. You can press the x0.0 button, see the answer, then press the x5.0 button, to get a multiplier of x2.0.
I do think adding a simple loping song would add a lot, and that is worth looking into for the next game jam. I know choosing a song is difficult (it was for me), but incompetech that Mark suggested really did work.