Drop the ball

You start from 2 balls and the last level contains 6 balls to drop.
This is casual riddle that uses 2D physics of round objects and obstacles.
This game is not hard, but some levels are tricky, so if you have 5 minutes of your time to exercise (without overload) you mind the riddle is for you.
I started creating games a few month ago and I need to provide to my family, so I added Unity Ads into the game.