Hellblade: Senua's Sacrifice is a single-player action-adventure game set in a dark fantasy world inspired by Norse mythology and Celtic culture. Players control Senua, a Pict warrior who journeys into the Norse underworld to rescue the soul of her dead lover from the goddess Hela. The game blends melee combat, puzzle solving, and psychological horror, with Senua's psychosis shaping how the world is perceived, including voices that provide guidance or attempt to mislead the player. The game was developed by a team of around twenty people and features no heads-up display or tutorials. Instead, audio cues from voices in Senua's head guide the player through combat and environmental challenges. The portrayal of psychosis was developed in collaboration with neuroscientists and people who experience the condition.