On this difficulty the ghost cap is 5 at a time, 4 on F1 and 6 during a blackout.
Ghosts in cleared rooms are 10 floors stronger during a blackout.
Shop items also cost 2 times more than on
Normal.
Smashables will not drop any
Hearts anymore, they'll drop something else instead.
Chairs are always angry at the player and there is a new mechanic you have to maintain during game-play or you'll die.