Free DLC (Updates)
- Planetary invasion - a bit more strategic depth and much more fluff but nothing major game changing features like new engine, tactical fights and so (has been discussed in multiple instances)
- Governors for both planets and star-bases. A must-have for very large universes which is basically the selling-point of the game
- Advanced fleet management options and perks - A streamlining and emphasis on fleets like the Total War series has done with armies would make large fleets with perk, crews and commandants with experience much more important. Management options could
- include the fleets functioning as way-point themselves for shipyards
- Return to nearest base or space station for repairs
- Management of perks and crews/commandants with experience
- Information on the history of the fleet
- Option to have a designated flagship and icon for the fleet on the management screen
- Spy system as a significant function. Since GC2 already included this it should be in for GC3 to be an evolutionary step including features:
- Steal tech, money or reduce production, influence or morale
- Secure votes for UN
- Spread tension between two civ
- Show planetary infos, ship locations and their targets
- Counter-espionage system
- Buildings to enhance offensive and defensive espionage
- CIV perks providing bonus on this aspect
- Diplomacy effect if spy cough
Paid DLC
- Additional CIVs with unique tech tree, buildings and ship parts
- Custom maps
- Single player story extensions
These would make sense in my opinion as they would not affect the AI significantly but would till offer value for those who are willing to pay more