First goal was to make game in that way that you need to take care of world by replenish trees and don't destory all of them.
But for the second thing I am a little confused because I am sure I took that away. At first it was capped at 100 material and then you'd have to upgrade but maybe I kept it in by accident.
I had a lot of fun programming it because it was something new and I was working on my old project for more than a year.