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