The camera hovers closely behind Castellanos. Many level parts offer multiple approaches, with the ability to silently sneak or to hide. While exploring jars of green gel can be picked up that act as upgrade points. By staring into a mirror Castellanos is transported to an asylum in his imagination. There the game can be saved and it has a chair where he sits down to upgrade weapons and abilities with up to five levels. Points can be spent to improve weapons with a damage multiplier, faster firing rate, shorter reload time, large clip capacity, improved accuracy or a larger chance for critical hits. You can also make more room for ammo or items, or use points to upgrade physical abilities such as more health, extended sprint time, more melee damage or large syringe recovery.
There are traps and bombs in the environment that can be disarmed to earn trap parts, used to craft crossbow ammo. Traps can also be left in a strategic way to limit the number of directions enemies can attack from. Enemies include animals, regular 'haunted' enemies, and a number of grotesque creatures. There are also boss fights. The game features three difficulty levels.