Oh wow, I really found myself getting into a flow state with this one. Tetris-plus-math is a great conceit, and everything here feels so polished. There's a lot of texture and depth to the core mechanics.
I did find myself getting the board under control after a while, and maybe another degree of difficulty ramp-up might be quite nice, but that's just a nitpick really. The sound design is understated, but works really well - after a while it begins to sound like music. It all just flows really nicely. Amazing work!