MMORPG idea

I have had this idea dancing around in my head awhile. It is a virtual world that would be a cross between the "Sims" and "Maple Story" and "Civilization". It would be a virtual world similar to our real world. The people in it would be "programmed" to start by players choosing certain attributes. They would have a "home base" area of their own. Perhaps a small village. When released in the world the players could no longer affect what they do, but only monitor. As more people were put into the game they would interact based on the selected attributes of the players. Some would kill each other, some would mate with each other, and some would ignore each other entirely. The player could alter the environment, however. They could make it rain, or force a deer to run toward their characters, for example. They could even affect other players' characters at the risk of retaliation. But ultimately the characters would "think" for themselves. What do you think?