This is a really cool concept and it definitely worked out my short-term memory! I do have one note that might help with UX if you decide to improve it in the future. I played the web version and found the controls a bit tricky. I couldn’t just click and drag, I had to click, click again, then drag, and be very precise to place the box. Because of that extra effort I kept running out of time on the last round, even after a few tries. I think with smoother controls this could feel even more fun, since the core idea is great!