This is BRILLIANT!
So simple and so hard!
I didn't understand anything on the first try. What do I control? What's happening on the screen? On the one hand, a small tutorial would be nice, on the other hand, the mystery gives the game a certain charm.
On the third try I realized which square I was controlling.
Around the sixth - what needs to be done.
It took about two dozen attempts to get a feel for the timing. It would be faster with a countdown sound, but it might not be more fun. Have you experimented with this?
And no matter how much you study, sooner or later you will get distracted and make a mistake. The game requires really strong concentration, a sense of time, and a habit of speed.