Nice game, I played it because it was a similar idea to mine, but the execution was super different and so good. I also got the square stuck at the bottom sometimes, and I think the biggest problem with that is it happens if you don't move the ball at all, so it's almost bound to happen on your first time when you don't know the controls too much. Maybe you could position the ball so it fall on the lever or some sort of ground just so the player has time to understand the controls better.
But the game was great. Rhe music and sound effects were really good as well.