(Hopefully) use difficulty as it should. The difficulty[0] (also called rank) varies from 0 to 32 and affects various parts of the game. The difficulty now impact those parts, but how it is modified during the gameplay is not clear. Such changes to the difficulty are not handled yet. [0] http://en.touhouwiki.net/wiki/Embodiment_of_Scarlet_Devil/Gameplay#Rank