Basically you plug in earphones, turn on this game and walk/jog while an audio-book like storyline goes into your ears, sometimes with music picked from your iPhone. But it's not always that relaxing.
Hear zombie groans or a message stating that you're being chased? Run like forget.
When you're finished you can pull out your iZombieSimulator to use items (that your iZombies picks up as you run/walk) to buld up your base and unlock new apparent missions.
It comes out in 3 or so days.
(source)
