User blog comment:FromDvToZombies/Zetsubou no Shima pre-release interview revealing a few details about Jason Blundell's thought proccess with DLC 3 and DLC 4's Zombies map./@comment-1187559-20160516165012/@comment-1187559-20160516234022

Since I don't have that many friends to play Zombies with, it often made many of the EEs uncompletable for myself. Also, I hated the ones that were behind really complex assignments, like getting a wonder weapon and shooting a random stone outside the map without getting told anything about it. And since the story is hidden in these so-called Easter Eggs, it makes it very hard for anyone to follow the story, which has in turn lead to all these fan-theories, not because it's a fun mode, just because it's left so overly vague.

I didn't mind the maps like Call of the Dead and Mob of the Dead, where it sort of pushed you towards what you needed to do, and wasn't weirdly complex.