When I fancy playing "proper" Spore again, I think I'll just delete all those saves and start a new one. It's a shame as I wanted to keep the Machubi - the race I created in the cell Phase when I first started Spore and then evolved through to Omnipotence in the Space Stage and got to the Galactic Centre, but since it seems there is no way to sort this problem, I'm not letting some other random species take over their save! :P
Anyway, my time is currently being taken up with messing around in GA, so I'm sure that'll keep me busy for a while yet
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