Eternal Darkness: Sanity's Requiem is a psychological thriller epic that follows the adventures of twelve characters across the world and two millennia. The forces of evil from beyond have been trying to manifest themselves in our world, and it's up to these forgotten heroes to save us. Chapters take place in Ancient Rome, Persia, the Middle East, and modern-day Rhode Island.
The game features an involved Magick system that allows players to create different spells by combining runes. These spells can attack enemies, dispel illusions, and heal both characters and items.
Eternal Darkness: Sanity's Requiem also has a unique feature called Sanity. When an enemy sees a character, their Sanity meter drops. As Sanity gets low, hallucinations start to plague the character. Walls bleed, voices whisper from nowhere, and the camera gets disoriented. Sanity can be restored by dealing a finishing move on a dying enemy, or with spells or certain items.