Complete the indicated task to unlock the achievement.

Achievement	How to unlock
A Different Exit	Find a secret level.
A Good Start	Get through The Graveyard.
Bye, Moai	Destroy the Moai in the Snow Cliffs.
Halfway There	Get through The Catacombs.
I Hate The Ghost King	Defeat the Ghost King three times.
Long Live The Queen	Defeat the Void Queen (Secret)
Quad Kill	Defeat four enemies at the same time.
Regicide!	Defeat the Ghost King.