Four Main Characters
Zombies
Special Weapons
There are many types of weapons featured in the Zombies mode, too many to describe. Therefore I will showcase a few of the special weapons also known as Wonder Weapons, most powered by Element 115.
The 4 Elemental Staffs of Origins, Fire, Ice, Wind, and Lightning. 3 pieces each to assemble and and be upgraded to an Ultimate Staff by solving a series of puzzles each having it's own unique puzzle.
Maps
In order the maps are Nacht-Der-Untoten, Verruckt, Shi-No-Numa, Der Riese, Kino-Der-Toten, Ascension, FIVE, Call of the Dead, Shangri-La, Moon, Green Run, Nuketown, Die Rise, Mob of the Dead, Buried, Origins. Most of these maps include the 4 main playable characters, if not then they are mentioned or the player somehow interacts with them. Also depending on what version of the map the main characters may or may not be present.
All of these components in Zombies take a role in addicting players to this game. Many people are attracted to the large variety of characters, zombies, weapons, and maps. There are surely many more in-game items that cause people to flock to this game but surely the release of a new map brings people in because of possibility of the zombies story line continuing.