Okay, so it wasn't technically a plot twist in the most literal definition, but Pokemon isn't a series that can exactly be said to have a strong plot. You play as a kid who wants to become a Pokemon Master and you go about doing just that, with later games adding onto the story with various side plots. Still, the heart of the game was meant to be a kid-sized adventure that would last forever, so you can imagine the surprise many of us felt when we arrived in Lavender Town and found NPCs mourning over the death of their best friends. The main point of games, especially Pokemon, is to be escapist outlets for people wanting to leave their world for another. Thus, being thrown back into reality made us all very disappointed. It can even be said that the shock felt by this revelation was the cause for all the scary Lavender Town myths you hear about now. Let that be a warning for inducing childhood grief.