Darwin eat your heart out
1) The controls are simple to learn. Even easir to use. Much of it being point and click
2) The Universe of Spore is ever expanding. Even if you decide to never upload your creations to the Spore webpage, and you decide to strictly play offline.....Any creation you've ever made will potentially show up in your own game. That's right, an early creature you created could potentially show up later populating a whole different world. Or as a herd animal during the Tribal stage.
3) How you behave in each section of the game determines special abilites you can earn.....Are you a social carnivore? A destructive herbavore? Out for conquest or make friend? These all factor into what kind of abilities you can get.
4) If you don't feel like creating something, you can just pick one from the Sporepedia. The Sporepedia has things you previously created, as well as things people uploaded
THE BAD
1) Creatures can look similar very easily since when you expand vertabre in the spine (or shrink it) you make the creature fatter or thinner for that area. There is no way to flatten it, so you can't end up with something with a cobra like hood.
2) Omnivore is not a starting choice, you actually have to earn it.
3) The inability to just hand paint your....err....Sporecreature is kind of a downer as that would have added a bit more fun during creation.
4) A few different shapes would have been nice to see in the Vehicle and Building creators
THE MIXED
1) When you complete a stage of the game you can, during any other game, start directly at that stage. So if you want to skip the Cell Stage and Creature stages and start at tribal you can. However the price you pay is that you loose special abilites you normally would have.
OVERALL
If you're into simulation/strategy games, this is definatly one to consider. It puts a fresh spin on a tried and true game genre. The "sporepedia" guarntees that you'll always find something new