This gave me an idea. It should be Like Dune II, you can't build large structures over sand or soft terrain.

What about climate? If there isn't a mod already. That should add a lot of dynamism; think of storms affecting your solar panels, or flooding (affected buildings wont work or less efficiency); dry seasons lowers your water pump; snow; etc... Survival features, drink water (water purifier) and food (...

A few ideas: After you launch a rocket, others factions (bots) should arrive into the planet. Creating it's own factories, vehicles, fighting with aliens and even at you. You could trade with them and make allies. Add more tanks. Or the same tank change the turret, armor, engine, etc... Tank should ...