This horror game comes with a unique gameplay mechanic: Occasionally you control two worlds at once, presented as a split-screen. Think of the worlds as two different lenses, or filters: You see the same area on both halves of the screen, but they're different. One is the living world, and the other is an underworld filled with death, and Marianne walks through both simultaneously. You use both worlds to solve certain puzzles: For example, when searching for items, you'll notice objects and areas will only appear in one world. Or, certain interactions in one world will make the other change (like unlocking a door), carving a new path forward.