Here is the full list of all 21 Boots Versus Plants achievements.
Complete the first level of the game.
Complete the second level of the game.
Complete the third level of the game.
Complete the fourth level of the game.
Complete the fifth level of the game.
Complete the sixth level of the game.
Complete Level 7 of the game.
Complete the eighth level of the game.
Complete the ninth level of the game.
Complete Level 10 of the game.
Complete Level 11 of the game.
Complete Level 12 of the game.
Complete Level 13 of the game.
Complete Level 14 of the game.
Complete Level 15 of the game.
Complete Level 16 of the game.
Complete Level 17 of the game.
Complete Level 18 of the game.
Complete Level 19 of the game.
Complete Level 20 of the game.
Find the secret at level 1