This is really cool. I really liked how it flipped when you died. Is the number of humans you can chase down the same as the number of zombies you evaded?
If you did want to expand on it, would be great to see some debris in the road, or even a third sequence where you start in a car and can run down zombies until the car breaks down and you continue on foot, but i'm just thinking aloud.
Great idea and great work!