I love the concept! A couple things drag it down for me, though - first of all, the ability to just drag objects offscreen and be done with the level ruins the challenge*. Also, I wish there was a way to skip the rest of the countdown. It becomes frustrating to wait for the timer to run out every time.
I think this has good potential! In context of the game jam, it feels underworked, although I understand that given the time (I only had the time to make one level in my game). Good luck!
*I've just realized that you became aware of the bug at the three hour mark. Did something similar with my own submission. The time limit is frustrating sometimes, huh?