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