Here is the full list of all 55 Ancient Dungeon achievements.
Lower your merchant discount to -100%.
Escape The Ancient Dungeon after re-entering once.
Escape The Ancient Dungeon after re-entering twice.
Traverse The Beast's Cradle without taking any damage.
Escape The Ancient Dungeon without consuming any food items.
Escape the Ancient Dungeon without entering a shop.
Throw a dragonfruit into a pit.
Defeat a boss enemy with a single strike.
Destroy one thousand pots.
Escape the Ancient Dungeon in under twenty minutes.
Open 250 chests
Defeat one hundred aberrant enemies.
Damage The Beast with the Assassin's Armament.
Acquire more than five full hearts of health.
Traverse The Infested Dungeon without taking any damage.
Traverse The Overgrown Gatehouse without taking any damage.
Traverse The Forgotten Library without taking any damage.
Use The Blacksmith's Anvil to augment a weapon.
Destroy a Sacrifice Statue.
Defeat a Mad Merchant.
Deal at least twenty-five damage with a single strike.
Eat every type of food item during a single delve.
Traverse The Luminous Mines without taking any damage.
Strike enemies with a ranged weapon twenty-five times in a row without missing.
Acquire three highly powerful items during a single delve.
Explore two hundred fifty rooms within The Ancient Dungeon.
Discover a secret room in the ceiling.
Damage The Beast with the Mercenary's Armament.
Acquire four items from shops during a single delve.
Damage The Beast for the first time.
Defeat a Possessed Armor.
Discover a secret room in the wall.
Challenge and destroy a boss with only a half-heart of health
Overcome a Challenge Chest's trial.
Defeat a Chest Mimic.
Enter The Ancient Dungeon for the first time.
Raise your merchant discount to 60%.
Discover (almost) all items.
Carry more than two hundred fifty coins during a single delve.
Use a Contracting Orb to shrink yourself.
Win big on The Merchant's slot machine.
Carry more than twenty keys during a single delve.
Defeat a Golden Slime.
Escape the dungeon without obtaining any upgrade items.
Escape The Ancient Dungeon after re-entering three times.
Damage The Beast with the Mercenary's Armament in hard mode.
Damage The Beast with the Assassin's Armament in Hard Mode
Use a Bandit Box at least twenty times during a single delve.
Fully augment the Assassin's Armament.
Fully augment the Mercenary's Armament.
Consume a food item made of gold.
Complete the delve of every Sealed Soul.
Complete 3 unique sealed soul delves
Escape The Ancient Dungeon with a difficulty modifier of 2.25
Escape The Ancient Dungeon with a difficulty modifier of 3.00