Well, I got an idea ... and then I just couldn't stop ... so now we have a bit of a zombie apocalypse on our test server xD.
Rules are quite simple: zombies destroy stuff, food heals houses, goods damage zombies, passengers to HQ does AOE. There is no particular goal yet or any scoring at all. And, honestly, there is no winning condition either, just constantly increasing level of zombies.
So at this point it's just an experiment that is still far from being a complete gameplay. But let me know what you think of it, what kind of new game mode we can make of it. Maybe citybuilder where there are no strict requirements but you need all that cargo to fend off zombies anyway. Also any small ideas would be nice as well, like I know banks are useless atm, mb they could buff towns so that houses get more HP. Or mb there needs to be some kind of ammo storage system instead of an instant damage for goods. Mb find some use for transmitters scattered along the map?