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