It seems to be a great game! Sadly, I think it encourages resource exploitation as to what we, the human race, have been doing to Earth as a whole.

I think a very good extension would be to provide new technology for sustainable energy generation and even further the ability to harness and excel the planet as a super living thing (as Asimov could imagine in its Foundation series).

This would provide an even more constrained and challenging environment as to maintain planet's equilibrium on one hand and progress on the other.

Maybe, those aren't really valid concerns from the beginning of a game. But afterwards, it'll be important as massive industrialization reaches ecological relevance.