It would be nice if Empires Apart had more Terrain functionality and diversity which could enable the players to manipulate the battle ground to help them gain advantages.
Maybe have bogs which slow units, especially horsemen. More impassable mountains and crevasses could add to the game as well. Maybe Hannibal as a hero could be able to cross mountains. (Bring the elephants!)
Bridges have been suggested, but It would be cool if only one civilization, or one civilization's hero, could build bridges. For instance, if the Romans are added, Julius Caesar could build bridges over rivers, like he did crossing the Rhine.