In my Total Recall piece on Dani Bunten last week, Cities of Gold was mentioned as being her only real commercial success, and I'm hoping this video shows you why.
Get past the crude graphics - it was released in 1984, after all - and you can see a vision and scope there that other developers wouldn't be scratching at for another decade. At the earliest.
The game was rich in customisation, strategy and exploration, and also touched on a period in history that few other games at the time (or since!) bothered with. You can see where Bunten's friend Sid Meier got a lot of his ideas from, as anyone who has played both Cities and Meier's Pirates! will see the influence.