From what I understand, this last update has been focusing entirely on Endless Mode, and all that pertains to it. The developer renamed the original gamemode to "Story Mode", and left it at that to work on the aforementioned content. I'm sure they have plans for it, though.
I hope that you add hidden backstory, needing to be theorized instead of said directly!
I mean, if it was all explained, that would be pretty nonsensical - the humans created the robots. (Unless they were from an alien force, but if that case, what was that blocky figure doing saving you?) The humans would have read the newspapers, they would have known what had happened, and even some might have created these robotic creatures.
