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