Here is the full list of all 12 Defenders of Ardania achievements.
Use the unit info 10 times.
Win a level without towers.
Destroy the Minotaur Base.
Sell 10 towers in a single mission.
Finish the first mission.
Build all tower types of one race in one mission.
Survive 60 waves on the Survival game mode.
Finish the Campaign.
Use all Economy Upgrades in one mission.
Win 5 multiplayer match in a row.
Complete all levels in Limited Resource mode.
Unlock all achievements.