My City is a very simple game that I like. What we do is we start with a city with no population at all, then we start to add citizens to it day by day, until you get a big city. Sounds boring, huh?
The fun is you can add different kind of citizen to it, depending on what is your city's current attribute. There are 7 attributes to a city: prosperity, safety, workforce, culture, science, entertainment and health. Each citizen you add, the citizen contributes to the attribute of the city. For example, if you add a hospital doctor to your city, you add +1 safey, +1 science and +1 health to your city. With different citizens added on and on, your city will build up with certain attribute and therefore develop into a certain style. You may have high entertainment and culture, but with low safety and health (like mine); or you may have high prosperity and high workforce, but with low culture and science, etc.
With different attributes to your city, different citizen will be available to your city, and some citizen will become unavailable. For example, serial killers come into play when your city have +10 safety and >= 10 population while hospital doctors disappear when you have > +40 health, etc. The fun of the game becomes trying to make some new kind of citizen available to you and so as to increase the demography.
You can also add citizens to your friends' city. The number of citizens that you can add per day to different cities depend on your population. The high is the population, you can add citizens to more of your friends.
Here is my city:
Please come and add some citizen to my city, and I will return the favor to you~
Enjoy and happy gaming!