I like historical games much more than fantasy and I really hope it will be about ancient times. So if I would choose between Rome and space game I would choose Rome. For now, my favourite game is ck2. Perhaps the game could have many different elements with very huge timeline extending from ancient era through medieval times, new era and modern age to future. You could start as Rome, for example and fight against other nations and develop your technology with historical limits in different periods of time (When I say historical limits I mean for example you cannot have guns in ancient times.). In the future you could explore and colonize other planets. Also you could stay on Earth and fight against other countries there. That would be very interesting, but I think that making game like that would be extremely hard and that game would be very very huge, so I think we cannot expect it now or in the near future. Just imagine how fun that game could be. For example if you play as monarchy with start in ancient times and play to modern days or future keeping your dinasty, and if you look at your family tree you can see all the monarchs who lead your country from ancient times to modern days and that would be awesome for me because I very like dinasty system. I think that many people would be satisfied with the game like that. I mentioned that only as idea and I am not sure if it is possible to make the game like that.
