The body of the player character houses an exchangeable (and depletable) battery that powers various body functions put there by the experimenters. Functions include a regeneration system that heals all damage when activated, as well as a powerful projectile weapon (known as the "PFD Prototype"). Upgrading and swapping the battery is key to the player's progress at certain points in the game. The player can also don a protective armoured suit that enables him to survive the harsh atmosphere outside the facility and explore the archaeological dig.