Complete Adventure mode.
Collect all 49 plants (including plants from Crazy Dave's shop).
Defeat your first Gargantuar.
Plant your first 10 peashooters.
Blast 10 zombies at once with a Cherry Bomb!
Win any level after all lawnmowers have been used.
Go trunk diving and spend at least $25,000 on Crazy Dave's Twiddydinkies.
Stop the horde using only the Sunflower, Wall-Nut, and Chomper on any level.
Complete a nighttime level without planting any Mushrooms.
Complete a daytime pool level without using peashooters of any kind.
Defeat a normal roof level without using any catapult plants.
Complete a daytime level by planting only Mushrooms and Coffee Beans.
Defeat 2 Gargantuars with Corn Cob missiles in a single level.
Bowl over 5 zombies with a single Wall-Nut.
Hypnotize the lead dancer zombie.
Get to a streak of 10 in I, Zombie Endless.
Get to a streak of 15 in Vasebreaker Endless.
Beat all 19 mini-games.