This week I bought Spore, When you first start the point is to eat. This is your objective until you reach Tribal Stage (My current stage) then it is to collect food and use it to build. Another Objective which gets you progress is to Attack/Ally another tribe. Then it is on to Civilization. (I will be there in about an hour). This game goes like this

Cell Stage: 7

Creature Stage 5-7 (later into creature stage 7)

Tribal Stage: 8

Civ. Stage: ?

Space Stage: ?