Here is the full list of all 44 Viking Brothers 3 achievements.
For canceling a task.
For gathering 500 units of wood.
For gathering 500 units of stone.
For upgrading 30 buildings.
For exchanging gold for mana 50 times.
For building 30 buildings.
For unlocking a tavern.
For fixing the Rainbow Bridge.
For earning three stars on 10 levels.
For gathering 500 units of food.
For destroying an enemy tower.
For exchanging gold for mana 10 times.
For encountering a patrolling enemy.
For not clicking the mouse for 30 seconds.
For gathering 100 units of gold.
For using the running booster 10 times.
For exchanging gold for mana.
For giving Vikings 300 tasks.
For gathering 100 units of wood.
For gathering 100 units of stone.
For giving the Vikings five tasks at once.
For gathering 100 units of food.
For using a booster.
For completing a level without using a booster.
For earning three stars on one level.
For using a booster 100 times.
For gathering 1,000 units of food.
For gathering 1,000 units of wood.
For gathering 1,000 units of stone.
For gathering 500 units of gold.
For gathering 1,000 units of gold.
For earning three stars on 30 levels.
For canceling 30 tasks.
For earning one star on one level.
For encountering 30 patrolling enemies.
For earning every achievement.
For unlocking five taverns in the main adventure.
For earning three stars while playing Chipmaster.
For finding Thor's hammer.
For finding Heimdall's sword.
For finding Odin's spear.
For finding the three Places of Power.
For helping the gods in the final battle.
For acquiring the Travel Amulet.