Hearts work as a 'lives' system within the game. You will need to have Hearts in order to enter and play Levels.

In most cases, you will start with five Hearts by default, as seen in the upper-left corner of the main screen. Each time a Level is lost, one Heart will be taken away; when there are no Hearts remaining, you will not be able to start a new Level.

However, Hearts do replenish over time, with the time remaining shown in the upper-left corner of the main screen. It is also possible to earn additional Hearts, by watching video ads or requesting them from friends connected in the game.

Additionally, it is possible to gain Unlimited Hearts for a certain amount of time within the game. You can win these from events such as Tournaments, receive them as part of Shop packages, or purchase them directly for Coins.

While this ability is active, no Hearts will be deducted for losing Levels, allowing you to play for longer without interruption. The Unlimited Hearts activate at the point the are received, and remain in effect for their set duration (including while the game itself is inactive.)