Yes, it's an RPG. Anyone who can't accept that premise can stop reading now. Okay -- item two: it's an RPG with a difference (which shouldn't surprise people who've heard of the author).
This is the 20th Century seen through cinematic eyes, by someone who has read a lot of cram notes on the 20th century, who isn't too worried about being sued if he gets the details wrong, and whose audience wants a good story, not historical accuracy.
So Queen Victoria is married to Albert -- Albert Einstein -- who does "Something with atoms", and the leading riverboat gambler of the era is Wild Bill Gates.
And since it's a game there are rules on how you can join in. So, you, too, can fly the sky with the WW1 aces Monty Python's Flying Circus, or adventure with the 7 Dw*rves, led by "Doc" Savage.
But the best part is reading the book and imagining more of the fractured future history of the last hundred years -- watching as (say) Lohn Lenin, Boy George, Paul Getty and "Ringo" Starwalker fight the Undead Legons with their Golden Discs, or the skirmishes of the Third-of-a-World War between the All-Black-And-Tans and their sworn foes, the bionic Springboks.
Is it too much to hope for a small expansion pack in a year or two ?