City Stage

The City stage of Spore was not implemented in the final game. Its main feature was to provide a new golden era of technology, architecture, and infrastructure to the player's city. It was supposed to come after the Tribe stage, but before the Civiziliation stage. Your tribe had became civilized, but motorized vehicles had not been invented. Even though it was not put into the final game this does not exclude the possibility of an Expansion pack or patch.

Agriculture
There would have been some form of agriculture in the game, but whether or not it would spark the rise of civilization like it did for humans is a different story. However, a few images from E3 2006 showed what appears to be a farm with silos outside of the city limits. Theoretically, herbivores would either go out and gather vegetables and fruits, or grow them in a farm or orchard. Omnivores and Carnivores may have made use of pastures to keep herd livestock, or go out and hunt for meat. In the Tribal stage, it is possible to domesticate creatures as a form of agriculture and you can farm fish.

Early on during a video on the Spore website, there is a reptilian creature tending a much larger dark green quadrupedal creature which was inside a pen.

Since the hidden text document leak it has been confirmed that all creatures (carnivore, omnivore, herbivore) would have been able to domesticate animals and eat the domesticated animal's eggs, like you can in the tribal stage.

Arts and Crafts
It is unclear if people could make their own unique culture or be able to make monuments and landmarks with their own race. If it was possible, however, there could possibly have been a way to create own art such as statues, paintings and architecture.

City types

 * Floating Cities were never made possible. interview with Gaming Steve
 * Living City
 * Moving City
 * Planet-wide City
 * Underground City
 * Arcologies

Crime
It is unclear whether or not there would have been internal crime or corruption in your cities, and how it would have been dealt with. What we did know is that if you killed or stole from another tribe, city, or planet, the inhabitants will lose patience and attack you when you are nearby or hovering over the star. There were probably many possible ways people could have dealt with crime. There could have been jail, death, exile or simply no punishment at all.

Pollution
Pollution is the presence of harmful contaminants in the environment. Though it is harmful, it is usually a necessary byproduct of development. It could be speculated that there might have been pollution as a small factor for happiness during the city stage if nothing else. (i.e. pollution dependant creatures or "dead" polluted worlds.)

Sports & Games
It was speculated if the Tribal stage would have had any sports or friendly competitions, whether they be between a single tribe or civilization or between two. If that were so, there would be the issue of whether or not people would be able to watch games without participating, or be able to interact indirectly with the game (like in Amazing Island).