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