One thing that I hated about spore creature stage is that it forces you to advance to tribal stage. In thrive aware stage, will you be able to remain a creature, or even a plant and just have fun with it?
^ My original character, Blob. Don't care? Keep scrolling
You can remain a plant/creature forever, if I remember correctly (Also, you could also just not advance to tribal stage in spore. I had multiple playthroughs where I just grinded until I had everything at max)