CrowdCity.io is a cool zombie themed IO game, that you can play online and for free on Silvergames.com. You will start by controlling a couple of bloodthirsty undead creatures and your goal is to attack living humans to recruit them to your zombie army. Once your group is large enough you will be ready to attack other zombies.
Take over each and every city and buy upgrades for your zombies, like speed, life or attack power, and unlock new types units. Kill them all, eat their brains and have fun with CrowdCity IO!