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.
Nightmare Fuel: At various points. The game's atmosphere is a bit unsettling to begin with, as you are playing as a little girl all alone in her house and you have no idea what's going on, but judging from the state of the house she's been alone for a while. Maybe. Although some of the beds are still warm... The house catching on fire, the frantic emails telling Leah to kill Birdy, and the ending are probably the worst of it.
Tearjerker: The ending, if you're not too busy staring at the screen wondering what the heck is going on still.