Some more ideas that were to be or not to be:
Drivable vehicles in the game demo → not to be due to time constraints. Though they will be there for players in the full game.
An incredibly complex single player story → we turned this down in favor of free roam with a series of 'story' missions. This in the end will free up man hours for the multi player platform.
Zombie virus travels in clouds, after zombies are killed the remaining virus particles lifts up into the air and flies away to an unknown location. → (shh!! ) This one's on the back burner. You might notice the zombie bodies disappearing into a black cloud in the demo. Now you will know what this is.