Set different goals, try playing in other modes as in normal and hard.
Some try to set goals to reach all skill levels except level 3 in spirituality.
Some try to get to a certain point before having anyone die.
LOL I have a game going where I keep all the females preggo when they are old enuf and if I have the "space" for more kids.
Another game I have going is I want to max out all my skills.
There are many different ideas you can try to set for yourself once you "finish" the game.