Essential Editor is as easy as challenges get. But, I get it - not every challenge is supposed to stump every player.
It's important to keep in mind that, when developing CTFs with a broad audience like KringleCon, you've got to build challenges that appeal to every level of skill and experience. That includes people who are just getting their feet wet in Information Security. And this challenge serves that purpose, because it is definitely designed for people who are just getting started!
Accessing the Challenge
This challenge was one of the first ones I encountered upon entering the gates. Clicking the challenge will display vi in a terminal. It shows a fun little message with simple instructions to "Exit vi."
Having knowledge of basic vi usage, I entered :q to exit vi, which solves the challenge.