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.
Doomed by Canon: Word of God confirms that this game takes place before Downfall. Seeing as how Joe slaughters everyone in his apartment building, that might include Susan. On the other hand, doubtless Susan is pretty Genre Savvy by now, and besides that, she knows that Joe in particular is violently insane. So it's just as possible that she escapes.
Esoteric Happy Ending: The good ending can be seen as this seeing if you have played Downfall since absolutely nothing is done to stop Joe Davis, and he will go on to murder everyone in the hotel, all except him are jerks at worst and pretty nice people at best.
Fridge Brilliance: It only makes sense that the Parasites flock around Susan: she lives in a rough part of the town, she has no friends, her entire family is dead by the beginning of the game, she is unemployed, her few neighbors would be happy to see her gone, so nobody is going to miss her and look for her. She is also very weak emotionally, making it easy to win her trust. She is a perfect target for any criminal.
Although Liz being Dead All Along does come as quite a shock, it starts to make sense when one replays her chapter. None of the nurses are ever seen talking about her or to her, the doctor who Liz calls over when Susan wakes up never speaks to Liz or looks at her, and the only other person who knows anything about her is Doctor X.
Fridge Logic: Everything about the Joe Davis sequence. Did he and Susan have a shared hallucination? Was Susan somehow transported into his inner world? Were they in some sort of alternate reality? What was that?
Susan did the same thing with Ann Burton's hallucinations (?) in Chapter 2, although she needed drugs to do it.
Hilarious in Hindsight: The reveal that Doctor X is a serial killer can be kind of funny if you've played Downfall, since it's pretty much the opposite of Doctor Z from the that game, who seemed insane and obsessed with dead bodies when you meet him, but is actually a good guy and Joe was just hallucinating
Harsher in Hindsight: Susan's hatred of flowers was pretty prominent, but one could assume it was just because she wasn't a huge fan of them. However, we discover in later chapters that Susan's baby died from a rare pollen allergy, triggered by the flowers Susan's stalker had given her. Thus explaining her hatred towards them.
Les Yay: Defied when Susan has a bath while talking to Mitzi. One dialogue choice has Susan only willing to let Mitzi in the bathroom if she promises she's not gay and doesn't stare at her chest the whole time.
Nausea Fuel and Nightmare Fuel: There's no point in listing the examples because a) they all are major plot points and b) the game consists almost entirely of such examples, with the exception of few Breather Episodes here and there.
Nightmare Retardant: Although the buildup to it is extremely suspenseful and creepy, what with the recreations of famous paintings using the corpses of women and the distant screaming of his victim, the actual reveal of the First Parasite can be this due to the somewhat clunky animation of him punching his victim and "dancing".
Susan's immortality can be this. For as frightening as the Parasites and Joe Davis can be, you're always aware that because Susan is immortal none of them can really DO anything to her beyond incapacitate her for a short ime.
Obvious Beta: You cannot overwrite saves, and there is a hard limit of 50 saves. In a game where Save Scumming is absolutely vital if you want the best outcomes.
Viewer Gender Confusion: Or, rather, Listener Gender Confusion: the pest control guy's wife. Being voiced by a man doesn't help, either.
Wangst: Susan is very guilty of this early on in the story. Justified as she is suffering from depression, had recently been brought back from the dead, and has several serial killers or dangerous people endangering her life and others around her. In the Epilogue, Susan has finally learned to take control in her life and is implied to be on the road to recovery from depression.
The Woobie: Every single sympathetic character really, really needs a hug.