Minecraft wiki entry for Zombie_Town, associated text: Notch's video of the game was called "Zombie Town", however, in his blog post he referred to the game as "ZombieTown".
On Twitter, Notch referred to the game on two different occasions, once as “Zombietown”,[4] and again as “zombietown”.[5] He also revealed that he had made around four different unreleased projects under the same name.
The original upload of the Zombie Town video was located here, but it has since been blocked, though archived versions are still available.