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