You automatically obtain infinite balls. The paid version costs $1.99 (£1.49).
If you run out of balls, you can wait a minute or watch an ad to obtain more. You usually get ten balls. If you complete a level, there is a 50% chance of getting ten extra balls. If you watch an ad after earning the ten balls, your reward gets doubled to twenty balls. Another way to obtain balls is to purchase them in the shop.
As players control their ball throughout the Rolling Sky levels, they are forced to face several dangers. Such dangers mainly include, obstacles in the level. Running in to these obstacles causes your ball to shatter making players have to restart the level they were currently playing. However, hitting obstacles is not the only way to fail. If players drag their ball off the road, they will be forced to start over due to falling. Occasionally, glitches may cause players to fail, however this rarely happens, especially depending the software being used.