- Alternate Character Interpretation: Despite the strong implication that Aya is following in her father's footsteps in the true ending, some fans choose to believe that she's simply become a kindly doctor. The 3.06 update to the ending adds on further fuel to the fire that she might not be going in her father's direction.
- Darkness-Induced Audience Apathy: When you learn the truth about every person in the game, including Aya given her future, it'll make you upset there's no ending where everybody dies.
- 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.
- The eyeless blonde that Aya helps almost looks like Viola. The only difference is that this blonde has blue eyes while Viola has green.
- The theory of Aya's clone being the library girl in Misao has become an Ascended Fanon through Continuity Nod, that is, if the player names the library girl Maria in the latest version of Misao.
- Moral Event Horizon: Aya's father crosses it when it's revealed he killed his wife, then firmly stays beyond it when he tries to kill Aya, and later, Maria.
- 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.
- During the last chase, Alfred will peek out from behind a door with a slasher smile and go "Boo!" Voiced and everything. It's supposed to be creepy and show him completely off the deep end, but it's pretty funny.
- Ugly Cute: Many of the undead minor characters can count, especially the "blonde boy". He is mostly a Bishōnen, but the Body Horror tries to subvert it.
- The Woobie: Aya and many of the Doctor's victims.
- Although Aya arguably loses this in the True Ending, seeing as how she may become her father's successor...
YMMV / Mad Father