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