When reaching a "Showdown" level at the end of an episode, you must click the "Showdown" button followed by "Begin boss battle" to fight the boss. At times it is better to postpone a Showdown level. Each time you complete an episode, your revive tokens are restored. If you are about to enter a Showdown with more than one life, use the extra lives first on standard levels to build extra rings. Then, enter the Showdown to refill your lives.