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.
Find a hidden weapon upgrade
Find a lore-unfriendly secret in Greece
Complete the museum without taking any damage
Complete Streets using only the flintlock and dagger
Die on Sightseeing Mode
Complete the museum level using only the dagger
Click one of the social links on the main menu
Beat the game on "Once Again" mode
Beat the game on "Goblin" difficulty
Beat the game
Get the wand at the end of Greece
Find a secret Impaler before Dracula's Castle
Kill an enemy with their own projectile