The one part of those old Greek mythos epics I enjoyed the most was the gods sitting on mount Olympus basically playing a game with the hero's lives. To that end I wanted to create a game where the players don't play the hero, but rather gods trying to guide the hero and help him, or obstruct the hero and hinder his progress.
I figure the hero would be represented by a figure who moves along a path that is created by location cards laid down by the players. If you want to help the hero, you would lay down little side quests that would help the hero gain favors or bonuses that would help him later down the road.
Another player might want to hinder the player by throwing obstacles in his path such as monsters or impossible tasks. each player would play their cards and then the hero would move further down the road. Players would get victory points for every challenge the hero overcomes or fails depending on how your playing. There could also be secret mission cards, since the good gods want to see the hero succeed to the end of the quest, the villain could have a secret, inscrutable plan that succeeds anyway. This could mean that the hero ultimately wins his quest, but the villain wins the game by completing their secret plan.. or something.