Here is the full list of all 16 Face It - there are A game to fight inner demons achievements.
Complete World 4
Complete World 3
Complete Lux in Tenebris without taking any damage.
Complete World 2
Complete World 1
Complete any level from darkest world.
Unlock the Reconnection Sigil.
Unlock the Vision Sigil.
Unlock the Truth Sigil.
Unlock the Love Sigil.
Unlock the Will Sigil.
Unlock the Passion Sigil.
Unlock the Fight Sigil.
Complete a level with only one point of light remaining.
Unlock any level from darkest world.
Complete any level without taking any damage.