The Elder Scrolls III: Morrowind is a sprawling, first-person, open-ended fantasy role playing game. There is a main quest but also hundreds of side quests (over 350 of them) and the game is completely non-linear. You can be a hero, a villain, a pilgrim, a saint or even a vampire. You name it, and chances are you can be it.
-Open-ended world allows you to follow the main plot from beginning to end, wander off in search of adventure in any way you see fit, or any combination of both
-World is centred around you. All the other characters change their perception of you based on your actions, allowing you to experience the world as an evil character or noble do-gooder with realistic repercussions and results