Re: how to change tribal and civ stage back to creature stage?

If you want to play as an advanced creature if I'm not mistaken you can use the cheat code(ctrl+shift+c to open cheat menu) EvoAdvantage before you start creature stage you can then select the creature. Though I'm not sure if it allows tribal and space outfitted creatures without cheat engine or a mod.
If you instead want the pokemon creatures with the tribal and civ parts to be polinated in your creature stage playthrough ,then I'm sorry I don't think it's possible.