In Spore the player has to accompany a new race through five stages of its evolution.
First there is the Cell Phase: From a top-down view the goal is to eat meteorite parts floating in the primordial soup to gain DNA points. But the player's creature is not alone and other, friendly or not-so-friendly organisms float about. If the player kills other alpha organisms, he unlocks a new part for the creature editor like a new mouth. These parts all give the player's creature different abilities including singing or a better attack and even affect what the creature can eat. As the player collect's DNA points, the creature grows and moves up into a higher layer of the primordial soup until he is big enough to advance to the next stage: the creature phase.
At the beginning of the Creature Phase the player needs to redo his creature in the creature editor with a new set of parts like feet or hands. Then the goal is again to collect DNA points by roaming the land and befriending or killing the other inhabitants. Again there can be additional parts for the editor found which are dropped by alpha creature that get killed either by you or other, bigger creatures. If the player chooses not to attack but rather talk to the other races, he needs to gain their trust by following their lead and doing what they do. While the lowest creatures see you as a friend already when you just sing with them, more advanced races require a high level in dancing and other abilities which are again gained by rebuilding the creature in the editor with the gained DNA points and available parts. Once the player has collected enough DNA points and developed a certain level of intelligence by doing so, he can enter the Tribes Phase.
From now on the player can't change the basic anatomy of the creature but instead has access to the tools and clothing editors. The game also plays more like an RTS from now on, requiring to control a group of creature instead of just one and building up a village. Interaction with the other tribes, defending the village and collecting food are the main goals in this phase. Once the player has conquered or allied himself with five other tribes, he can enter the Civilization Phase.
Now the player has access to the building and vehicle editors to further specialize his former tribe and become the ruling civilization on the planet. The basic gameplay and controls remain the same as in the tribes phase but by conquering or befriending other nations, the player's civilization now gets access to new technologies - including the one required to enter the fifth, last and longest phase of the game: the Space Phase.
With his ship, the player now needs to go out and colonize or conquer the whole galaxy, defend his own planet against other space faring nations and supply his race with enough food.
The game doesn't have a real multiplayer. Instead the planets are populated by creations that other players made in their game. The players can choose to upload their creatures and even the whole planet to the online database called Sporepedia and from there they get distributed to everyone. Once downloaded, the AI takes over the control of these creatures and advances them further.