User blog comment:Damac1214/Thoughts on the Black Ops 2 Zombies series/@comment-67.106.127.25-20130710082940/@comment-1055346-20130710110120

Per Marbel, there is nothing in the game telling you to do the Easter Eggs, you could easily ignore them if you wanted. They're just there to give you an option beside straight up survival. Me and my friends haven't even done Green Run, Die Rise, and Buried's easter eggs, and we only did Mob of the Deads because it ended the game without death.