Lol. They were running out of ideas since black ops 2 tranzit.
Its got to be done, the last part with the dad has a plan thing has to just imply its before the zombies creation. At any point they are kids, so most of the storyline was not made by them, and just the box, jugs, heros, and the weapon outlines, which kids can create, not complex equations like solving the ultimate fire staff.
The map's name is origins as well, which implies that this was way before Cod: WaW.
As I said before, a lot of people are having trouble figuring out how this was all a game, and IMO, it wasn't. This was just two kids playing, and as time went on in the real world, it really happened. This was at their child like mental state however, as Samatha gained control, she was older, however he appearance never differed, but older. In this process she could have thought up many complicated things like everything that occurs in the zombies maps.