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