Most of us are familiar with the ingredients by now. It all begins calmly enough, a happy group laughing and joking before the screw steadily, inexorably begins to tighten. There’s an agonisingly slow build, a gradual sense of creeping dread, and that awful sinking feeling as plans go horribly awry. Along the way, there are unexpected twists and turns, the odd jolting shock, desperate races against time and a final, frenzied climax. Developing a game, it turns out, has plenty in common with the established structure of horror cinema.