Reverse Zafehouse?

To start, I have to say that I love zafehouse, it's a massively addictive game. However, once I finally succeeded in keeping my survivors alive, I began to consider alternate game modes. The one I like the most is the idea of the player controlling the horde of zombies that you normally fight.

You get given a set number to start, something small, and you have to destroy the plucky group of human survivors that keep trying to escape. More zombies could gather to your cause as the hours pass by, and any humans that you kill become your loyal zombie servants.

To prolong the game past the original 60 hours, side objectives could be achieved, such as destroying bridges used by the rescuers and contaminating fuel to stop helicopters from taking off, increasing the amount of time that humans are stuck in the town.

It appears as though there has been little activity on the forums recently, but I would appreciate any feedback on my idea, and perhaps some advice as I try to create this reverse zafehouse myself, with the source code that has been so generously provided.