The concept of God has made its way into many games. Such as
Black and White:
You play as a god to a village of people who worship you. The more you bless them (build houses, increase resources, food etc) the more their numbers increase. You "Jesus" comes in the form of a animal which you teach using hand motions. The more powerful you are (more worshipers) the bigger your animal.
You can play as a good god or an evil one (Black or White). You also have to battle with other gods and their worshipers.
This PC game is very fun and addictive.
Spore: Spore isn't a God game per say but it does involve "Intelligent design, evolution, terraforming etc...." You can play god in a since.
The opening scene begins with a ice comet traveling through space until it crashes onto a planet. This is where you being, as a simple cell who must eat and survive in a pool of other organisms doing the same. As you grow you get new body parts to increase various attributes. Each time you mate you are able to change your organism which eventually become a sea creature, which eventually goes on land, evolve to a tribal being, to civilized being and lately to space traveling being.
Once you begin space travel, you can travel to the various stars in your galaxy (there are hundreds if not thousands of stars). Each star may have planets of beings in any of the stages you came from. You can also terraform planets to make them habitable for you civilization to spread. Each player creates their creatures and can upload creations from other players connected to the Spore server.