These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Fanon: Various fan theories have been concocted attempting to tie Mad Father to Misao, which is set in the same universe in the future. Some of these include Ogre being Onigawara, Aya or her clone being the Library Girl, and Alfred Drevis being the Mad Scientist.
Hell Is That Noise: Aaaayaaaa... Doko ni iru no kanaaaa~?Translation Aaaayaaaa... Where are yoooou~?
Narm: Some of the scares can come off as this thanks to the limited graphics.
Aya's character model can often fall victim to Dull Surprise and her mother's has slightly crossed eyes in some of the shots of her.