Simple gameplay that works! There didn't seem to be too many hiccups with the hole following the mouse. The offset between mouse and the hole took a little bit to get used to.
The shadows clearly show which object is falling. Sometimes the smallest-looking shadow wasn't the lowest one though.
The "edge" of the play area was too unforgiving, making you lose when you were barely touching the edge. I'd recommend allowing the player to get at least a third, maybe even half of the hole outside before game over. You could also give it a short timer (0.3 - 0.5 seconds maybe) so the player doesn't "die" immediately - the suddenness of the game over felt weird.