This is based on opinion. Please don't list it on a work's trope example list.
Tear Jerker / The Longest Journey
White Mother's death.
When April sleeps in the Banda village and at night her Evil Twin who is really just a projection of her worst fears appears and belittles her to the point of despair, a projection of Charlie appears and tells April she is not alone on her journey and is loved.
The entire atmosphere of the second half of the game, when April is risking life and limb in a quest where her reward would be to shut herself off from the entire world for centuries, with no one she'd ever met knowing what had happened to her to be phenomenally depressing.
The last scene, in which the old Guardian shrugs at April and essentially says, "Oops! Our mistake, you can go home now. Thanks anyway." After all the time spent telling April she's important to the fate of the world(s), it's a Player Punch to see her dismissed like that.
As part of her final tests before entering the Tower of the Guardian April has to face her biggest fear which she herself might not even be aware of. As it turns out, she is turned into a child and her biggest fear is no other than her creepy, possibly drunken father, obviously ready to abuse April some more. The whole scene is not only surprising as April's difficult relation with her father until that point seemed to be just part of her background with little impact on the actual story,note It's important to note that while you can browse through April's journal to learn a thing or two about her family life and while at the police station you can use the videophone to call your mother, you don't have to do either of those things. but it's also very touching as April manages to convince her father that she knows he cares deeply about her even though he has trouble expressing it, as well as to actually forgive him years of abusing.