OK! I'm going to be making a few tutorials to be able to play spore a bit my way. (Highly strategic, so no fun for people who don't really like to play it like that, but still helpful!) Anyway lets get to the tut!
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Now! That meteor is you. And to be able to become that galactic God/Goddess you should start with Carnivore (Sorry Herbivores you can always switch later...or never =P)
Ok now once you get out of your rocky shell eat the current meat/other cells in the area, once you get enough points for the herbivore mouth, buy it. NOW! With your new found herbivore mouth use it to eat plants an your carnivore mouth to eat meat and other cells. (Also do not buy the omnivore mouth as that will limit your eating range.) Now once you have gotten enough parts to upgrade again you should go with speed first then defensive/offensive tactics (If you have it by now go with electric attacks, if not spikes!) Once you have your desired cell with the proper upgrades go on and finish the cell stage.