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