You play a character whose job is to collect souls for the grim reaper. This is because the grim reaper is only one being and cant be everywhere at once. So you go around fighting off demons who try to claim souls, because you have to collect enough souls to take to the grim reaper so you can go to heaven as opposed to hell where you’d be going if you hadn’t accepted position as Death’s minion. The only thing you have to fight the demons with is your sweet magical sword and your unholy powers, such as breathing fire and summoning undead to fight the demons for you. As you progress through the game satan sends more and more powerful and cooler demons and mortals endowed with satanic powers to kill you and have your soul added to his vast collection. Eventually, with the aid of Angels (Angels in this game would have to look really B.A.) you fight satan himself. Of course you could avoid fighting Satan depending upon what you do throughout the game. Everything you do throughout the entire game, determines the rest of the story. Like killing one random person on the street, or blowing up a random car, could change the whole story.