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