Distorted reality

A distorted reality where you, the players are stuck in a giant simulation controlled by some anomalies that we call 'the under people' because they are rumored to be living in a place under the overworld. In the overworld, there are several islands surrounded by water on a small, limited platform. On some islands, you will find dangerous, blood thirsty killers that want to kill anyone they see. On one of the dangerous islands, we found a mysterious portal which we believe goes to the secret place where the under people control the simulation. For several years, we've been sending people through the portal but every time they never come back. We don't know what had happened to them but it's up to you to figure out.