Trigaea

In Trigaea, you are thrust into a world where you recognize nothing. Not your surroundings, not the artificial voice that claims to have awakened you, not even you yourself. When all that remains is the vast, hostile plains beyond the shelter of a sprawling metal labyrinth, you must steel yourself, step outside, and find out where - and who you are.

Trigaea is an epic 272,000-word piece of interactive fiction. It's a combination of a sci-fi novel and an RPG adventure game, where you are in control of the story.