E.V.O.: Search for Eden is an interesting video game on the SNES that has the main character evolve into a human and ultimately take up residence in the biblical location of the Garden of Eden. It was published by Enix and developed by Almanic. The goal of the game is not only to evolve, but to become the dominant species so that you'll be allowed into eden.
In E.V.O., the player will scroll to the other end of the area, performing what ever needs to be done. There are various stages in the game, or ages, that will have you play as a fish, an amphibian, a dinosaur, a mammal, and finally have yourself inside of Eden. Each stage's character plays differently, though each character is required to eat downed enemies in order to get evolution points. Evolution points will give the player a variety of upgrades that will dramatically help them throughout the game. Like Spore, a recently released game, you are given the ability to modify your creature however you like, rather than having them change in a preset way.