Nice start, but there are some things that could be improved otherwise I understand this game is still in a WIP phase.
The direction of the ball should be controlled by the mouse and not a 'slider'
Second, the physics aren't quite right yet, when the ball rolls back on a hill the backwards movement caused by the physical gravity stops at a sertain moment. It sounds weird but the ball just stops at the middle of a hill which mostly isn't possible. On the otherhand, this could be possible when the ball consists out of metal and you hold another metal object close to the ball without touching it, so the magnetic flux will interact and make the ball go slower but the movement of the ball will never stop because of the force caused by the natural gravity
That to the side, I hope you can finish this game and make the best out of it !!
Cheers
Frazzle