Evolution in Gaming Addiction: Flow and Spore

A while back I came accross a simple (yet strangly addictive) game on the web. As a part of her master's thesis, Jenova Chen created Flow. The game is a sort of organic Pac-Man. You start out as a miniscule organism with a big appetite. As you swim through different layered levels and eat other organisms, you grow and evolve. Your enemies (or prey) vary in size and shape from the small single celled flagella propelled creatures to large (and quick) sting-ray like animals and strange circular creatures. The larger creatures actually attack you in this "kill or be killed" game. If you can escape the reach of your enemy's mouth and turn the tables, nibbling at your enemy, your enemy breaks apart into smaller organisms that you can then prey upon. Over time you grow longer, stronger and faster. If you play long enough, you can actually try evolving as another creature. I've gotten as far as evolving as the circular creature after about 30 minutes of game play.
When I first played Flow, I noticed some similarity in concept to another game that I heard about which will be released in Fall or Winter '06. The maker of the Sim City games and the Sims, Will Wright, is creating a game about evolution (and civilization) called Spore. A video on Google Video shows the game in action. The concept is the same as Flow at first. As your character evolves, however, it grows legs and moves onto land where the game develops further. The game then turns into tribal mode. As your tribe develops, you move into "civilization" mode and later into "colonization" mode where you explore other planets in space and either destroy them or colonize them.
Part of the appeal of this whole concept is the same for me with the Sim City games: starting simple and building a complex system. Perhaps games like Flow and Spore will create a new trend in evolution simulation games. Personally, I can't wait to see what happens with Spore.