To do this, its REALLY lame, but some just play great games to beat them. To beat the game in like... an hour, you need to first get the Keening and Sunder. Don't bother with the Wraithguard, you won't need it. Next, make your way into Dagoth Ur, and find the devil himself. Kill his first form and make your way into the heart's chamber. Find the first and slash is madly. The Keening and Sunder both do mortal wounds of 100 damage, so have MANY potions with you. Kill the heart and bolt! You just beat The Elder Scrolls III: Morrowind.