Well, first, it’s a pun on the popular tabletop game Arkham Horror.
The first idea about a locative game was born out of frustration. I am a pen & paper roleplayer (also called tabletop role-player). A couple of years ago, I would have had to say “I was”, though, because once I graduated from university and started a job (at university, being a doctorate student in Germany is actually a job with contract, work hours and all) time to play got sparse.
I realized that at least in my case leaving the hobby be was not because I had grown out of it, but rather because organizing a group of players, preparing the game, sticking with a given setting over a potentially long time, and so on is a lot harder to do when you have less time on your hands.