Here is the full list of all 13 Chop Goblins achievements. It takes around 2-3 hours to unlock all of the achievements on Windows.
Beat the game on "Once Again" mode
Beat the game on "Goblin" difficulty
Die on Sightseeing Mode
Complete the museum without taking any damage
Complete Streets using only the flintlock and dagger
Complete the museum level using only the dagger
Beat the game
Find a lore-unfriendly secret in Greece
Click one of the social links on the main menu
Get the wand at the end of Greece
Find a hidden weapon upgrade
Kill an enemy with their own projectile
Find a secret Impaler before Dracula's Castle