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