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