Looks great, is that tin and bronze in the ui? :) There might be a need for structures that are built in between hexes, such as roads, irrigation canals, walls, etc.
I also think that copper and tin should be finite, to help drive a need for colonization and expansion. Limestone should also probably be finite, though I don't think it is as important. It would be interesting to have forests that regenerate slowly unless completely harvested, though that might not work well at the end of the day. Copper ore (malachite) is a dull green color, I think that deposits should match that shade.
I'm excited to watch all your progress, can't wait to get my hands on the new sim.