The player’s goal in each level is to search for notes and logs from the hospital’s past, referred to as “remnants”, by looking for markings using glow sticks. Once all remnants in a level have been collected, the player is able to acquire a “sigil”, an item of significance to the hospital’s past, such as a teddy bear and a Bible. Bringing the sigil to “the Seal of Shadows” will unlock the next part of the building, allowing the player to advance further into the hospital and, possibly, to freedom.
Discovering remnants can cause a marking on her arm, which attracts the dangerous “shadow people”. The player can either make them disappear by using flares or lose them by running away. The player cannot access any weapons; the only tools available are glowsticks, flares, and a cell phone. The environment layout is randomly generated. The enemies and other antagonists are procedurally spawned.
The game’s interface includes the number of remnants the player has to find and the threat level in the hospital. As threat level increases, monsters are more likely to appear.