It's pretty good. Just adding my two cents in, having a destroy button would help in some balance. Just to help prevent situations where me building a bunch of factories at the start force me into having to keep doing so as the planet was dying too fast for me to save. Literally killing it so I could win. Probably not the message this is trying to send.
The years that pass by is something I think can be expressed a little clearer. I don't really know how long is considered a year, unless I'm dreaming and each actions is considered a year or something.
Great game to play. :)