They don't really do a lot with the history though and its basically the same historical progress with the addition of Walkers and some other pulp-tech.
I have to disagree here; it is just not completely over the top like later Weird War backgrounds.
IMO it is one of the best background just because it is only slightly altered.
But all the weird stuff is in, walkers, supersoldiers, zombies, oni, power armour soldiers, rockets SS trooper, US helitrooper etc etc etc
Also please bear in mind that the story line is not finished, it stops somewhere during late war, the "end" is open...