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