This is a really good game and I'm surprised not more people have played and rated it yet. Smooth and well designed with good RTS-like controls, decent upgrade system and extremely satisfying to watch your swarm grow and delete the humans. Would love to see more mechanics like the car that force you to control/micro your zombies more. I would honestly pay for a fuller version of this game.
Played for 15mins and ended up gathering hundreds of zombies to try and kill a car, didn't succeed but was fun watching the entire swarm get smushed :)