For those who did not have the patience to wait for the almost 3,100 frames posted occasionally over the course of four months, Jack Pryor built a website xkcd 1190 - Time at your own pace that lets users interactively step through every frame one-at-a-time or automatically, even with pauses to read dialog.
Randall Munroe explains the backstory here. It's truly an impressive work. While he does that I'll post some of the map-related images from the story. I'll leave the links only for the images that would be spoilers.
This is just before the big reveal. You can kind of see what it's all about if you know what to look for. To avoid spoilers I'm only going to post the link to it.