The first stage of the game is a pacman-like stage, called the "Tidepool Phase." Once your creature has eaten enough, it will be given the ability to lay an egg. The creature that's born out of it can be customised almost completely, while its animations are calculated dynamically. After that another generation of creatures is born, and they too are entirely confirurable. With the editor you can make almost anything, and the game will figure out a way to make it work. Due to procedural programming techniques the data files are very small.
After the creature's getting smarter, you will be taken to the "Evolution Phase," which focusses on battling other creatures and making yours stronger. It has a bit of a Diablo-feel to it, and is much about growth and development.
Next is the "Tribal Phase," in which you control an entire colony of your creatures that have become smarter. Instead of evolving the creatures themselves now, you can give them weapons or fire. An editor similar to the creature editor can be used to design new buildings that fit your needs. You can also download and use buildings created by other players though.
The "City Phase," that follows is like a small version of Wright's own SimCity. It's time to develop the city, and add roads and buildings for your creatires to live in. Once you've finished there, it's time to zoom out and enter the "Civ Phase," which like in Civilization puts its focus on influencing other cities to put them in your control. This can be done using military, economic or other means available to you. And once your creatures conquered the whole planet...
The "Invasion Phase" is the final one, which you can get in after developing a UFO (which you too can design yourself). It's the most sandbox-like game, after a more goal-oriented game in the first few stages, and this phase is potentially endless. Using that you can start taking over other planets, or even solar systems. Simply drop a creature on a planet to start invading it. After conquering a few planets it's time to move on even further, and look for other intelligent life in another solar system. Using radio waves you can search for that. The game populates the universe using content created by other players, which suggests an internet connection is necessary to play the game. It's up to the player what happens, and how you get in touch with the aliens.
Editors at sites mentioned earlier say the game is extremely different from known games. It's a new way to design games, and it's even unlike other sandbox games. Whereas for example SimCity and the Sims are continuously open-ended, Spore starts off more focused on goals, where the player has to develop a creature and city using editors as every other player - until you have that UFO. It's unsure whether Spore will be out on PC only, or if (next generation) consoles will also see the game. For more information check the following articles:
See some screenshots from Jesperjuul.dk, 0600Design.com and 4Gamer.net below. Note that these have been taken with cameras from the presentation, and as a result are of lower quality than the actual game. Thanks to SimsZone, SP Zone, SimsExpress and The SidDog for all the links.