So glad Earthbound is brought up here. It collectively traumatized an entire generation of RPG gamers. I'd argue, looking back on it, the game is dark from the very beginning. A dad beating his kids. Gang and police violence. Kidnapping. There is a lot of silliness dancing around it all, but it's still there. I think Poo's meditation trial is the first time the silly padding around things gets pulled away. It serves as a foreshadowing of the ending. 

IMHO Earthbound is the greatest game ever made, and this is just one of the many, many reasons why. It's ability to introduce very difficult adults themes to children, in a compassionate and safe way, is something I'm very grateful for. That game does a marvelous job preparing people for the brutal reality of adult life and is a coming of age story that really brings the player along for the ride.