Get Peking Express in under 5 seconds NOT ON THE IPAD VERSION.
Get over 1000 flags in all endless modes
Kill over 3,000,000,000 zombies
Get over £999,990 coins before level 3-5
Complete all Minigames without a bite from a zombie.(Note: Exclusive Minigames and Zombiquarium don't count.)
Build 24 Cob Cannons in a single Non-endless level
Complete all Survival games only using plants obtained in Day levels
Get 42 chocolates( When you have 9 chocolates, get 2 chocolates on-screen at the same time, then collect them. Then collect chocolates until you get to the REAL limit(42.)Apparently CHOCOLATE is the answer to life!
I have not completed any of these