The zombie game mode was introduced in Call of Duty: World at War, which was released for the PlayStation 3, Xbox 360, and PC. If you're looking for zombie game modes on the PS2, you may want to explore other titles in the survival horror genre.

Call of Duty: World at War from Activision for the Sony PlayStation 3 completely changes the rules of engagement by redefining World War II gameplay.

According to the acclaimed author, there are three levels of horror: The Gross-Out, Horror, and Terror. It is these elements that allow the genre to be diversely shocking and hypnotizing in not only literature but in cinema as well.

Terror is usually described as the feeling of dread and anticipation that precedes the horrifying experience. By contrast, horror is the feeling of revulsion that usually follows a frightening sight, sound, or otherwise experience.