The core mechanic is extremely fun, the levels are quite diverse. Good balance between too tough and too simple. You have to experiment a few times, and then you inadvertently stumble upon a solution. 

One thing though is a little annoying: the controls to charge the ball. You have to wait too long for the ball to charge even at 30-35%, and wait too long for the ball to travel to the destination. Other times, it frustrates to charge the ball to the exact percentage you need. I humbly propose two solutions. First, maybe you can make the game just a lil bit faster? Like 20 or even 10%. Second, you may consider other controls to charge the ball, for example, dragging the mouse while pressed away from the target location. I understand that it would be inconvenient to return the mouse to the exact location, when you messed only with the speed, but the direction was right, but that you can solve with repositioning the mouse location when spacebar is pressed.

Otherwise, the game is FUN. Had a great time.