Hello!
I recently extracted the game files of a PC visual novel called Ayakashi Gohan by honeybee and came across the character sprites. The png files are great but they all have pixels all over the sprites, which the msk/mask files seem to hide. And I think the msk files also give the sprites...
Only thing drive me crazy is all these new horror games nowadays is its so dark, all time. I can't even play them. I understand they trying to create spooky but be creative a little, not just darkness with pop out scare scenes.