Hello there, 
The project is progressing well, and it's now the time to reveal a first gameplay concept : the pandemic management
Zombies will first spread accross the world by using infestors. Those special units are cloaked and hard to detect. They will try to reach a city close to them, to initiate the pandemic oubreak. At this point, human nations can deploy some troops to try to detect and eliminate them before they reach the cities.
An infestor as a target in sight
However, if an infestor reach the city, it will earn a infestation point. Zombies will now begin to proliferate, and decimate the local population. Thus, the city population will daily take casulaties, that are proportional to the infestation level. Contaminated humans will then reinforce the regional zombies forces, allowing them to create hordes, and buying new infestors...
Even worse, The city infestation will increase more in more automatically during time. It represents the disease outbreak growing faster and faster. And this is made proportionnally to the amount of population in the city.
The infestation is growing in Marseille
So the player is now in a vicious circle, with a ever-growing infetation. In this case, what are the options to keep control over the situation ?
-The player can buy some ambulances and send them in impacted places. They will allow to reduce the infestation level. This is a first measure that will allow you to gain some precious amount of time.
An ambulance is arriving to relieve the population
-The other solution is to evacuate the cities population, and regroup them inside refugees camps that you previously built. Those refugees camps are indeed very less exposed to the infestation growth. Because it is easier to keep an eye on the population parked there.
With time going on, the player will also unlock new technologies that will allow to limit the disease progression, and to improve the ambulance efficiency.