It is very, very simple. You start at location 0.0, then use WASD to move any direction you want. You will come across inputs other players have placed at seemingly random locations, but as you move further, you'll find white feathered pens, that when fully highlighted, give YOU the opportunity to leave a positive message or short story.
My only criticism so far is that because there is no User ID, there is no author attribution, everything is anonymous unless signed by the player in their 300 character limit. I've personally come across messages of other players even trying to communicate, asking "Who's there??" My other concern is that if the app updates, what happens if all the inputs are wiped?
Ultimately, I enjoy it and people who enjoy creative writing or inspiring others will enjoy getting to add to the game. Others will simply enjoy reading others inputs. There's no goal, no experience, just words frozen in time.