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