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