Here is the full list of all 15 Wild West Crops achievements.
Defeat 25 enemies.
Defeat 50 enemies.
Defeat 100 enemies.
Defeat 150 enemies.
Defeat the first Boss.
Defeat the second Boss.
Defeat the third Boss.
Defeat the fourth Boss.
Open 1 treasure chest.
Open 5 treasure chests.
Open 10 treasure chests.
Open 15 treasure chests.
Get 25 coins.
Get 50 coins.
Get 100 coins.