How on earth do you trigger the other scenes for each monster? I can tell by the preview pics and by the victory room that they have other scenes, but how do you trigger them in actual gameplay?
Also, the game is rather buggy, as everyone else has mentioned. Monsters will typically only spawn after you leave a room when hearing the chase music, and if you quickly go to another room before it spawns behind you, it tends to just not know where you went. The box in the final area will softlock you if you interact with it from the wrong side, you must interact from it from above for the first push (to push it down). Not doing this will prevent you from controlling your character, needing to press f5 to reset to menu. The butterfly thing, if you intentionally don't save it, will actually respawn after you defeat the first monster. Despite it obviously not having an effect at that point.
I feel like it's sort of a bug, but the final enemy can never be defeated. Also, if you fail to do the thing to save the final girl, you are locked into the running away ending. The others actually don't force this, from what I can tell. (You still have to save all three in order to get the good ending).