Look up the list of console commands, the one's you want are unlimited size/scaling, unlimited complexity, the one that lets you start the creature stage with ANY creature (not just the basic parts), and the ones that let you set your attributes (IE, what your results are at the end of every stage).
I agree, Pred. That was the worst. I was watching spore since the very first demo of it by will wright, who, by the way, is no longer working at EA last I heard, and I KNOW that he's not working on spore. Since the first demo, they took two years to finally release the damn thing, and knowing how big EA was, we were all 'WHOA. This is gonna be huge if a company that big took so much time on it.' But no. In fact, they cut out two of the stages they previewed! One was a 'fish' stage between cell and creature, with full 3-axis movement in the oceans of your world. The second was the civilization stage, which was supposed to be two stages, an age of exploration stage and an information age stage. same map, different objectives and abilities.
The problem, IMO, is the target audience. We were led to believe that Spore was to be this epic, massive game that could be enjoyed by adults and kids. But then they seemed to say 'screw it', and simplified it down to insanely dumb levels, which coincidently let them release it sooner. OK. Then they said Spore is going to be this MEGA-GAME, and we're gonna release all these $7.50 expansions that expand the game, allowing you to add to your favorite parts, or improve the ****ty ones, or even add new stages. What did we get? Creepy and Cute DLC, and the Galactic Adventures expansion, which, to my knowledge is a creature stage ported to the spacestage, only you're locked into little instances, and have to complete a single objective in a little 2 minute mission. And this is SEVERAL years after Spore was released. They just let it die, which frankly is probably for the best.
Check out Yahtzee's Zero Punctuation review of it.