Last time i tried only one multiplayer kind - in battle mode. But multiplayer could exist in geoscape as well. This is first idea...
One problem, appearing there, is there to get antimatter, if there is no aliens with costful fuel.
Possible solutions:
- aliens still could appear on earth, playing against all players (no difference, what structure or base to attack)
- I have found some way to get some good amounts of antimatter, which i will describe below... (this tech could appear in campaign after final mission - like some bonus).
It may be not known, but based on known processes. Source is... synthetic back hole. When i googled for how black holes vaporize, i found this: eventually photones turn to protone-positrone pair, being at the edge of events horizon, in this case one particle remains inside it, another - outside of particle hell. Vaporization speed is reverse-proportional to black hole mass and rotation speed.
Now some requirements for antimatter production station.
- Black hole probably should be enough hard to keep generation speed in some acceptable margins (probably it needs to be orbital object, combining both antimatter generation station and refueling station).
- If station is not supposed to be never stopped, it must be resistant for short energy stress, going from disappearing black hole.
- Otherwise - another feature appears: destruction, abandoning or another termination even leads to good explosion, comparable to thermo-nuclear.
- As option, several stations could exist and be neutral (be available to all players).
