Here is the full list of all 31 Iron Fisticle achievements.
Collect 100 treasures
Collect all hint books
Complete a room when entering with only 1 health
Kill 10 enemies using dash
Reach max level
Collect 10 golden goblets
Get garlic breath
Get the golden turd
Kill a golem
Make lemonade
Complete the game
Get the golden bananas
Collect a giant piece of cake
Complete the third floor
Collect 1000 coins
Collect all rainbow gems
Collect 5 diamonds
Collect 100 items in the ledger
Complete the second floor
Complete the bonus game
Open 100 chests (any type)
Complete The Graveyard
Level up ten times
Collect all letters spelling B-O-N-U-S
Kill 1000 Frankies
Complete the first floor
Complete a room without losing any health
Buy a gold item in the shop
Complete The Catacombs
Complete the first room
Level up once