Here is the full list of all 9 Fancy Skulls achievements.
Complete the game taking exactly one point of damage
Stop touching the ground and kill 3 enemies without landing
Transmute 12 objects
Do not pick anything up, but a single coin and keep it to the end of the game
Kill 12 enemies with mannie's homing mines
Earn all crowns on one floor
Complete the game once
Complete level 6
Complete level 3