Here is the full list of all 40 Archvale achievements.
Defeat the Old King.
Store over 10,000 gold in the bank.
Reconstruct the gateway to Archvale.
Obtain Avarn's Sword.
Collect all Heart Containers.
Collect all healing flasks.
Defeat the Banished Executioner.
Defeat the Colossal Skullbot.
Collect every badge.
Complete every trial.
Defeat the Sunken Queen.
Fully upgrade a weapon.
Equip a shark cap and mermaid tail.
Assemble the Arch Lexicon.
Obtain the best potion recipe.
Cash in 10 treasures.
Defeat the Grove's Blight.
Destroy the barrier guarding Tanglegrove.
Defeat the Rotted King.
Survive the ritual of the Molten Rift.
Defeat Frankenslime.
Defeat the Exiled Wizard.
Defeat the Soul Serpent.
Defeat the Fallen Pharaoh.
Complete half of your badge collection.
Craft 30 items.
Defeat 1000 enemies.
Own 8 hearts.
Defeat Mongo.
Defeat the Queen Duneworm.
Defeat the Ghost Crab.
Restore 10 fountains.
Die.
Enter the Twisted Caverns.
Obtain an improved healing recipe.
Defeat Maxilla.
Perform five consecutive dashes without stamina recharging.
Complete your first trial.
Defeat the Great Slime.
Find the village of Timberwell.