Start Counting Heads Cause You Need To Have 20 Or Less Kids At The End Of A Level.
- This Means You Can Have 22 Kids, Lose 2 To Greedlings, Then Finish The Level And The Achievement Unlocks.
I Advise Doing This Early In Your Campaign, As The Greed Get Tougher Later, And Defending With A Small Pool Of Archers Is Rough.
- I Did It On Map 2.
- I Also Did The "Beat A Map With Only Two Builders" Achievement On The Same Run.
Athletes Bike Charging Ability, Plus Some Decent Barricades - Will See You Through Until You Get The Siege Breaker Built.
Good Luck!