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