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