Personally I don't think we ever need another middle ages "Age of" game it's been done twice now and the setting and game mechanics have been explored and thanks to the DLCs even over explored. Age of Mythology has been done and it has been done well so I don't need more of that any time soon even if it is a great game. I don't think Age 1 and 3 offer all that much change so I would go farther forward in time, at least to the time of powered flight giving us a new domain to fight for up high in the sky. (also no more melee pathfinding would be great)
Getting to play with helicopters, airplanes, rockets, zeppelins submarines and aircraft carrier would give us new ways to play the game without changing the basic economic system we love in Age 1 and 2.
Going to the future would be interesting since it gives a lot of creative freedom but playing RTS games over multiple planets never really worked well for me, turns out it's hard to visualize round objects on a 2D plane without making it look like islands with black water so it would have to be in asteroid belts or something like that.
Fantasy would be cool but much has already been covered in Age of Mythology, still a viable option in my opinion.
Getting to play with helicopters, airplanes, rockets, zeppelins submarines and aircraft carrier would give us new ways to play the game without changing the basic economic system we love in Age 1 and 2.
Going to the future would be interesting since it gives a lot of creative freedom but playing RTS games over multiple planets never really worked well for me, turns out it's hard to visualize round objects on a 2D plane without making it look like islands with black water so it would have to be in asteroid belts or something like that.
Fantasy would be cool but much has already been covered in Age of Mythology, still a viable option in my opinion.