You start off with 100 lives. Every time you click on a enemy you get a point in Enemies destroyed, a knight is worth 1, a witch is worth 5, a dragon is worth 10, and a wizard is worth 15. If you click on a unicorn, you will get an extra 10 lives. When the enemies reach the end the lives go down by a certain amount.
Thanks to Evanjohnson822 for the original project.