Complete the following tasks to unlock the corresponding achievement. To view your achievements and stats in Steam, select "Community", then "My profile", then "View all my games", then the game and view stats.

Achievement	How to unlock
At First I Was Afraid	Survive over 30 minutes in a Castle Defense game.
Blotting out the sun	Complete Chinese Campaign level 7 with 15 or more Rocketeers alive.
Bull in a China shop	Cast a boulder that does not damage a single unit.
Cooking by the Book	Complete the Viking campaign.
Fort Knox'd	Prevent the Giant in Aztec Campaign level 2 from reaching the Goldmine.
Fourtification	Complete Viking Campaign level 7 with all Towers intact.
I'm No Kung, Fool!	Complete the Chinese campaign.
Keep Your Lousy Army	Complete Aztec Campaign level 10 without taking control of the Viking army.
King of the Stone Age	Kill all Vikings in a Boulder Mode game without killing any of your own.
Lacking Balls	Complete Aztec Campaign level 8 without using a Boulder.
Lost Vikings	Complete Chinese Campaign level 8 without killing a single Berserker.
Pity the Fool!	Survive Viking Campaign level 10 without the help of Mr. Thor.
Planet of the Ninja Apes	Complete Chinese Campaign level 3 without a single Ninja death.
RickRolled	Destroy the enemy castle with a boulder.
Social Viking	Play 10 matches online.
Son of Norris	Kill 36 units with a single unit.
Techno Viking Dances Away	Reach the maximum distance in a Berserker Run game.
Uncontrolled Demolition	Destroy a tower under construction with Rage.
V for Veggies	Complete the Aztec campaign.
Where are the Kangaroos?	Complete Viking Campaign level 4 by destroying the enemy base.