As Gary Jules said, it's a very very mad world. And you are caught up in it. Welcome to Kalopsia, the world where everything is not as it seems. You are the seemingly sole survivor of a virus which has driven the rest of the world mad. Existing in a society that they adhere to rigidly, outsiders are not welcome, and are killed on sight
You are an outsider, and it is your job to survive this mad world. Thankfully, insanity means these people aren't very smart, so they won't be able to tell that you are sane if you act like them.
The aim of the game? To survive. Fool them, evade them, and find other survivors. But get caught out of line, and it's fight or flight, and they will stop at nothing to murder you.
Gameplay features:
Image source: http://indius.org/wp-content/uploads/2015/04/indius-we-happy-few-2.jpg