An ambitious effort falls flat thanks to forgetting gameplay elements.
When you start off Spore, you're small speck in a big pool, trying to find smaller specks to eat, or possibly some green vegetables if you're a herbivore. You'll also have to avoid some of the bigger things in the pool, dying doesn't seem to affect the game at all though. All in all an unrewarding experience that's over pretty fast. Once you've eaten enough you'll develop legs and get up on land, once there you'll... eat vegetables or hunt other beings if you're a carnivore. It's also possible to impress the other creatures and ally yourself to them. All in all a pretty unrewarding and boring experience, battles are almost like mmorpg ones, you just spam skillbuttons whenever the cooldown is over. Or if you want to ally yourself with the beasts you'll just have to watch the same animations over and over in order to either, charm, sing, dance or pose to impress them.
Once you've befriended or eaten enough you'll develop once again, this time you enter the tribal stage. Which is a little like Settlers. You'll have to find food from either trees, or hunting down creatures running about, or fishing. This food you can use to either get new babies for your tribe, whom eventually will grow up and become a new member. You will also be able to build some nine or so buildings, all adding some equipment for your creatures. Some equipment make you better at gathering food, some are better to impress enemy tribes, and the others are used for just killing the enemies completely.
This stage was probably the most fun, but as with the other stages it was way to easy. Once you complete this stage you enter civilizationmode, and this will push you into a simplistic rts-mode. This mode was rather tedious, and didn't contain much strategy. You did get to design your own buildings and vehicles though, which is alway enjoyable.
All in all, no mode is very complex, they're all very simple, by design I'm pretty sure. Personally I like more indepth games, but as I said, kids or people not into depth will enjoy this I'm sure.
The games graphics are cartoony and nice, the animations are fluent, and probably the games greatest achievement, considering that you made all the creatures yourself. The online component is sort of fun, but doesn't add much to your game.
Can't complain about the sound either, and at a later stage you even get to compose your own themesong.
All in all, Spore is a game that gives you the opportunity to make your own creation. It doesn't let you play a very advanced game with it, and for me the appeal of making creatures wears out pretty fast, and the gameplay is far to simplistic for me as well.
I'm sure alot of people will enjoy it for a longer time though, and I guess you won't know until you tried it yourself.