The series is a collection of first-person, cooperative puzzle adventures developed by the Dutch indie studio Total Mayhem Games . The series began as a student project at the Rotterdam University of Applied Sciences, where the initial game was created in just 14 weeks with a goal of 1,000 downloads. It exceeded expectations by reaching 10,000 downloads on its first day. Core Gameplay and Mechanics

The series is defined by , where two players are separated and must communicate using an in-game walkie-talkie.