Nice game. I liked the drop down system, where the choice of drop column also affects the next number to drop.
I thing the core matching mechanic can be figured out with some trial and error. But I had some difficulty understanding what the floating was about. It seems to affect only the 1's, as far as I could tell. And I couldn't tell when the floating bar would rise, etc.
Regarding making it more understandable, I'm not sure of any other way in the game itself; some tutorial may help though, especially for the floating.
Well done overall!