First of all, your game is really fun!
It feels really satisfying to click because of the animation and the sounds. The styling in general is really nice!
However, I needed a little bit of time to figure the mechanics out.
For everyone else: You have to click the button every time the orange square is as big as one of the white squares. If you timed it right every time, another square is added. Later on, there are other colors so you have to click the right button.