Spore is a game where you make a creature and it evolves. Eventually you get into space and interact with all the previous stages of the game.
In Spore, you play the game throughout five different "stages". Stages are sections of the game that have distinctively different playstyles. You start out in the cell stage, however, after you have completed one stage, you can start another file from that stage instead of the cell stage.
The cell stage, unlike the other stages, is the only two-dimensional (2D) stage, and is viewed in a top-down camera style. You start off with a cutscene showing a meteor-shower which brings you, a tiny cell to your home planet. From there, your creature expands, as either a carnivore, herbivore, and later an omnivore. You win the stage when you grow legs and walk up to land.
The creatures stage is 3d, you can add legs, arms, charming parts, weapons, and more. You can befriend other creatures, or attack them. Also, occasionally spaceships appear and try to abduct you and your friends. You win this stage when you become smart enough to make tools.
In the tribal stage, you can command your units, and befriend other tribes, or destroy them. You can add buildings, and customize your tribesmen. This is the first stage where your creature cannot be customized, but rather clothes can be applied to them. You win this stage when you either destory or befriend all the rivaling tribes.
In the civilization stage, you can command your vehicles, planes, or boats. You can buy cities, take them over, or convert them, all while capturing spice gysers that help you generate more cash and expand your borders. You win this stage by building the first spaceship.
You can colonize planets, fight enemies, terraform, interact with other empires, and kill the Grox (the most evil galactic empire in the game), all in a freely customizable spaceship. This is the only stage in which you can interact with other planets not yet in the space stage, and does not end or have a final goal, except to reach the center of the galaxy.
This is a tetris style stage that not much is known about, preceding every stage including the cell stage.
This is like the civilization stage, and precedes it, except you focus on your own city, and managing it rather than interacting with the rest of the globe.