The concept is interesting. I can't get past the second level though and I have to close and reopen the game to restart because you have no way to go back/pause.
Easiest way to do it is have it show up when the ball falls on the wall/ground, with a retry and home/level button. This could be a better placement for your ads too.
The ball in general is hard to control. Especially in that second level, I can't even get it to the side of the screen to drag it up.
Make the ball follow your finger instead of letting it lag behind.