Here is the full list of all 38 Iron Crypticle achievements.
Complete 10 Waves In Endless Mode
Defeat A Boss Without Using A Weapon Pickup
Finish A Regular Room Without Using A Weapon Pickup
View 20 Item Descriptions In The Ledger
Defeat The Phantom
Defeat Madame Tentacles
Complete The Mud Pits
Defeat 3 Types Of Miniboss
Collect 1000 points worth of coins
Destroy A Fire Bug
Defeat A Boss In All Its Incarnations
Find The Golden Kitty
Use 10 Different Weapon Types
Pick Up 10 Hearts In A Single-Player Game Session
Clear 50 Rooms Of Monsters
Defeat Hexapod
Use 5 Different Scroll Types
Get Rainbow Power
Complete Castle Crushers 3 times
Complete An Infestation Room
Collect 1000 Food Items (Increasing Score Type)
Collect 30 Lemons In A Single Game
Defeat Boulderface
Buy 10 Items In A Shop
Defeat A Boss Without Taking Any Damage
Defeat The Giant Peepwort
Defeat 1000 Monsters
Get 100 100x8s In A Single Game
Collect All BONUS Letters
Finish A Non-Boss, Non-Empty Room Without Taking Damage
Collect Or Buy 5 Stat Increases In A Single Game
Complete The First Floor On Hard Difficulty
Defeat Gnasher
Complete The Graveyard
Use The Atomic Fist 20 Times
Complete The Catacombs
Get The Golden Poop
Find A Map