[@Nerevarine]Actually, we also have sci-fi settings and the "Civilization" RPs kinda cover the Ancient age era.

Albeit something set truly in the Classical Age like Romans, Ancient Greeks and such could be fun.
Civilization type RPs have some of the tech but none of the culture from this era. It has tiny nations just struggling to survive.
So yeah, there isn't any true Classic Age NRP.
Hope you support some fantasy elements, though.