King's Quest: The Mask of Eternity

It is a time long ago, and magic and myth are embodied in every living creature roaming the world. Unicorns graze in forest meadows, wizards concoct mystical spells, and kings and queens manage thriving kingdoms. An evil being has summoned a spell to break the Mask of Eternity--the global icon of truth, light, and order--and a piece falls to Earth and is discovered by you, a youth called Connor. You pick it up, and everyone else in the kingdom turns to stone. You must gather strength and courage and set out to reseat the Mask of Eternity and restore law, light, and order to your world.

Unlike traditional 2D adventure games of the past, this third-person-viewed 3D game allows you to peek around any corner, push and pull objects, open doors, wade into rivers and lakes, and even fight with other characters. But make no mistake, Mask of Eternity is not a shoot-em-up game. The open environment allows you to live the unfolding story, even if you need to fight your way past evil characters to advance the story.

This (much larger) demo is closer to the eventual final release of the game, according to Sierra.