Full list of all 12 Plants vs. Zombies achievements worth 200 gamerscore. It takes around 15-20 hours to unlock all of the achievements on Xbox 360.
Complete adventure mode
Collect all 49 plants in the game
Grow the Tree of Wisdom to at least 100 feet
Defeat your first Gargantuar
Bowl a winner with a friend in Co-Op Wall-Nut Bowling
Survive 40 waves of pure zombie ferocity
Plant your first 10 peashooters
Go on a 5 game winning streak in VS. mode
Blast 10 zombies at once with a Cherry Bomb!
Win any level after all 5 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, Wallnut, and Chomper on any level