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