I really really appreciate how clever this concept is when you really start thinking about it. The added consideration of which block to drop on which other block adds so much. At first I wondered if there was a hidden timer that I didn't notice that increased every time I dragged a bigger number into a smaller one. Then I realized - it's an emergent timer! The act of dragging a big number up to a smaller one physically moves the whole block upwards, giving you more time till it hits the ground. The fact that this timer mechanic is a natural consequence of the core mechanic is wonderful, I love it so much!