Eternal Darkness: Sanity's Requiem

Eternal Darkness: Sanity's Requiem is a psychological horror video game released for the Nintendo GameCube. Developed by Canadian developer Silicon Knights and originally planned for the Nintendo 64, it was first released and published by Nintendo on June 24, 2002 in North America. It was the first video game published directly by Nintendo, rather than a third-party developer, to be rated M for mature by the Entertainment Software Rating Board.

The game's setting is centered around a mansion in Rhode Island, the home of the protagonist Alexandra Roivas' grandfather and the mysterious book known as The Tome of Eternal Darkness that Alexandra finds there. The game is presented in a third-person action-adventure perspective in which the player must navigate a number of locations as twelve characters spanning different time periods. The game utilizes unique "sanity effects" to enhance the gameplay.

Though not a commercial success, Eternal Darkness: Sanity's Requiem was widely praised by both critics and fans, even winning the "Outstanding Achievement in Character or Story Development" award at the 6th Annual Interactive Achievement Awards, presented by the Academy of Interactive Arts & Sciences.