Like in reality i’d like to see elevated and “sunken”(not underground) stations so you can build more realistic railways through cities just above or below street level, and with the “entrance point (road/building)” at normal level so that you don’t have to make weird steep roads down up/down to the station. I think that would be nice!
And as mentioned before, i’d like to build curved platforms/stations!
Other than that i think the game is close to perfect!