Once all objects in your current city are built, you can advance to the next one.

You can view all of the cities that you completed on the Map.
To view your Map, select the Map icon in the lobby’s main menu on the right of the screen.

You can build objects using Tokens. Tokens are earned by successfully completing solitaire levels. The amount of Tokens required to build objects varies. You Token balance appears on the top left of the game screen.