Man, SierraLee does excellent writing in all of their games. I was especially wowed by John's depressed perspective, as I felt that I could better understand a real-life friend after that. 

It's a tad weird that there's little detail to the world outside of John and Lizzie, but there's tons to explore there, so I don't mind that emphasis. (Lizzie probably made sure there weren't any other characters to distract the player. How kind of her!)