It's one thing that feels lacking to me in the concept. If you're going to stretch the map out to a solar system rather than a single square chunk of land on some anonymous place you need to start thinking about orbital units. Here's a bit of brainstorming I've done on the subject of orbital warfare. Let me know what you guys think. Spy Satellites That's map hax people. Say goodbye to the fog of war, We see everything. This small but potent high tech unit gives your team what every general has dreamed of since the dawn of time. Unlimited map awareness. At least until the enemy shoots them down with their rockets. Ground to orbit missiles All them darned pesky satellites have to die. No need to go up there and deal with it personally, we can build missiles and shoot all that stuff down! Orbital Weapon Platforms While you're in the business of placing satellites in orbit, why stop at simply spying? Why not put lasers, or kinetic bombardment weapons on these suckers? Single out and pulverize your enemies from space. Naturally, these being mere satellites, cannot ever be as potent as moon based or asteroid based weapon platforms, but they certainly should have their place in things. Hunter Killer Satellites All these pesky satellites in orbit need to die! Why not send up intelligent killer satellites that can fly around and kill those other guys satellites. Control the space above your ball of rock. Don't let that other guy build stuff up here. Orbital Constructors With all of these orbital goodies, you need a constructor built to navigate its way around in space. Fitted with limited directional rockets, this little guy can fly around in space and build all them fun things you want to put in orbit to blow up them other guys.