I Walk Alone

Difficulty: Very Easy-Extremely Hard

I Walk Alone is an achievement unlockable on Plants vs. Zombies Adventures. It requires the player to win a game of Plants vs. Zombies Adventures while only using one plant.

Strategies
The best way to earn it is to replay The Boonies Level 1. Plant one Peashooter where it can hit the zombies easily without being attacked too soon. With sufficient luck and clever use of Gardening Glove or Lawn Mower, it is also possible to achieve this in other levels in The Boonies. It is mostly impossible in later levels. If not possible, wait until other plants and VIP plants are unlocked to easily earn this.

Trivia

 * This achievement's name is a reference to the song, "I Work Alone".