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