Money

Money is used to buy items from Crazy Dave's Twiddydinkies.

Currency
There are three types of currency: These are worth $10, $50, and $1,000 respectively.
 * Silver coin
 * Gold coin
 * Diamond.

How to earn Money
Money can be earned in several ways: Note that some of these can also give you Zen Garden Plants or Chocolate.
 * Killing Zombies
 * Completing Levels (always)
 * Eating Brains in I, Zombie (always)
 * Every three levels in I, Zombie Endless
 * Every ten levels in Vasebreaker Endless
 * Adventure repetition levels
 * Zen Garden Plants