Each change you make to your custom setup increases or decreases the games difficulty percentage. This means that if you make your city on a mountain or with higher elevation, the difficulty increases. You can choose the amount of water you wish to be surrounded by, the amount of vegetation and the initial population. Having a high population surrounded by water on a big hill makes the game a bit harder to complete. Life in your city is never easy for the people.
Housing is limited, work is scarce and it s often hard to find food.
The people will not stand by and wait for you to make something happen. They will demand elections were some greedy, arrogant peasant would rise up against you. The advantage is that you can rig the election. Your party will generously slide votes your way and attempt to win the election for you. If the people get fed up enough and feel they are not being heard, they will rebel and you better have a damn good army.