I was thinking what if we could keep advancing and maybe even go past the 21st century.
I know it'll be difficult and complicated but I was thinking something along the lines of empire earth.
There could be underground resources such as oil etc. when surface resources run out in the later ages.
A tree plantation to grow more trees?
Open cut mines?
What do you think?
Would it be hard to implement firearms?
This could be a long term goal of 0 ad?