Wideload's Matt Soell did an interview with GamingNexus about Stubbs, covering the idea behind the game and some of it's features:

At that point it seemed obvious that what we wanted was a game where the player could create that chaos and destroy Rome in a day, so to speak. Games are full of zombies, but they're always the bad guys – so obviously a game from the zombie's point of view was long overdue. Everyone is familiar with the idea of zombies – how they act, what they do – but they've never been in the position of thinking like a zombie. So it was a way of doing something that was different without being a totally foreign concept.

As mentioned elsewhere, Stubbs does have a cooperative play option, but lacks online multiplayer.