Here is the full list of all 20 Defend Your Life achievements. It takes around 15-20 hours to unlock all of the achievements on Windows.
Kill 1.000 enemies
Win one level
Kill 2.000 enemies
Kill 4.000 enemies
Kill boss
Kill cancer
Kill 40 duna worm pro
Build 200 towers
Build 600 towers
Build 200 tesla towers
Build 100 artillery towers
Use 150 bonus electroshock
Use 150 bonus bomb
Use 75 bonus adrenaline
Win level in the brain
10 buying in the store
Destroy the bridge
Call 100 waves early
Get 100 tablets
Get hero to level 50