Unopened "King's Quest: Mask of Eternity" Windows PC CD-ROM computer game developed and published by Sierra Studios, released in 1998. The point-and-click action-adventure game, released as the eighth official game in the King's Quest series, was billed as 'one of the year's biggest and most exciting new adventure games' by Computer Gaming World. Encapsulated and graded by VGA as "NM+ 85."