This really has never been tried on iOS and its a nice start. The concept is there but its still needs work.
-The map is too small for sure it could be made multiple times bigger
-Cars dont work well
-Zombie Spawn is bad to fast and compressed
-Inventory bar needs work so it doesnt move the screen
-More items for crafting and possibly even the ability to build shelter
Vaporicer dah boss about Pixel Z - Gun Day