Here is the full list of all 12 Flipping Death achievements.
Unlock every character in a chapter
Have a character stay scared for 20 seconds
Finish the game
Complete "A Black Day for a Blacksmith"
Complete "Death of a Woodsman"
Complete all challenges in one chapter
Unlock all ghost cards
Mindread 40 characters
Make someone Happy within the first 60 seconds of a chapter
Make a character feel all the emotions (Happy, Scared, Angry)
Help Captain Heropants catch Dr Laser
Fall down from the highest point of the town