A feature that would be great would be to allow players to populate the space terrain around planets within a certain limits and of course at a certain cost (production cost plus maintenance) along with the "traditionnal" planetary defenses. The closest thing I could think of in those terms would be something along the line of Sins of a Solar Empire (but in TBS of course). Each planets would have a base military infrastructure points based on : Planet size Infrastructure development? Racial abilities and scientific achievements Planet specials such as rings, moons, etc... Within the range of those points players could build Space station(s) Fighter bases Missile batteries Gun batteries Repair and support drone bases Mines Force fields, asteroid, gravity well that would provide terrain blockers or cover (mobile or not) Slow down ships Directional force field that allows to shoot from behind etc... To spice things up Allow the building of secondary planetary defenses on moons (more planetary guns, more missile) Have the ability to "hide" ships within planetary rings or "behind" planets Planetary rings would provide bonuses or maluses depending on composition and who is shooting where. Fighter bases hidden within planetary rings Therefore you could mount decent defenses against invasion around important colonies or obvious target for enemy conquest. And if Shipyards are going to be implemented, a poorly protected shipyard, could become a target and cripple one's war machine with a carefully orchestrated hit and run attack.
I can see where this could lead to some interesting and fun sophistication, even Moo2 has Starbases as orbital defenses. This approach as suggested by Bigmo would add a greater variety of units for the player, more building options and generally increase the activities a player could engage in.
