You begin the game with five lives. Once you lose a life, you must wait a half-hour for it to be restored. If you run out of lives, that can mean a long wait. However, you can adjust the time settings on your device and skip the wait. Just close the game and then set your device's time forward a half-hour for each life you want to restore, up to around three hours. When you load up the game, you will find that you have your five lives back. After that, you can return the device's time to its proper settings, if you like, and the restored lives will remain.