Here is the full list of all 16 Defense Warfare achievements.
Destroy 1000 trees
Unlock 3 perks
Unlock 7 perks
Buy a tower
Buy 5 towers
Destroy 500 trees
Collect 1250 credits
Collect 2500 credits
Win 5 stars
Win 10 stars
Win 20 stars
Kill yourself with the "Sudden death" button
Win a game with 1 HP left
Win a game with only one tower equipped
Find and destroy the super secret golden Humvee
Win a game