Hollowed tells the story of a woman who will do anything to bring her perished loved one back to the world of the living. The player will control a humanoid character named Halia as well as a spirit named Oco simultaneously on one controller. These two characters are tethered by a spiritual connection and they must work together to progress through the daunting challenge of saving Halia's perished loved one. While Halia has the ability to jump and move, Oco has the ability to help Halia in her endeavors through four unique abilities. Use these abilities to interact with the environment and Halia in order to progress through platforming puzzles in this 3D side-scrolling adventure.
The mechanics allow for a new way of exploring the side-scrolling genre by asking the player to control two characters simultaneously. Halia's controls take up the left side of the controller while Oco's controls take up the right side of the joystick. It is only through the synchronous collaboration between these two characters that the players will succeed in helping Halia save her loved one.