For a checkpoint piece, take a look at the image below, and make some kind of list: flat, multi-level, inline, vertical, matrix, simple, detailed, unordered, ordered—whatever you like.
You can decide what items to collect and how to categorise and relate them!
You don't have to limit yourself to what you see; this is a list about a make-believe world. You can think about events, processes, feelings, history, whatever.