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