Here is the full list of all 26 So long as there is Mercy achievements.
Burn all spiderwebs in the bathroom
Burn all burnable objects in the bathroom
Burn all spiderwebs in the attic
Meet Izumi
Burn all burnable objects in the attic
Burn one object wich is not puzzle relevant
Burn one Spiderweb
Meet Lucien
Meet Jivan
Meet Kimya
Say farewell to the GC
Find your lost brother
Hear every story from the GC
Sacrifice Spé
Sacrifice Mercy
Carry the toiletpaper form the bathroom to the final room
Carry the pot from the attic to the final room
Carry all 3 Books form the attic to the final room
Burn all spiderwebs in every level
Burn all burnable objects in all levels
Carry all objects to the last room once
Get all Achivements
Burn all spiderwebs in the basement
Burn all spiderwebs in the kitchen
Burn all burnable objects in the base
Burn all burnable objects in the kitch