... how does a virus spread from walking/swimming? ;
Anyways, I can easily see how it spread from Kanto to Johto because they're connected, but the other regions are pretty far off... so I don't really think it could actually spread like that. Plus there's the whole quarantine issue. Also, one more issue I see is, if the virus spread that easily to all regions, how did it not affect the Orange Islands? Orange Islands is pretty near to Kanto/Johto iirc, so there's a lot more bigger chance of it being affected rather than Unova itself.
Also I'm pretty sure scientists would be working on a cure. There is an area sealed off... there should be like a research facility there.
@PkmnTrainerYellow: No, they can't really be considered that way... Being a zombie means you're practically brain dead now. And you really need some power of your mind to use powers like blowing fire, or shooting water. And since zombies in Resident Evil are like... half rotting anyways, I don't really see how they would be able to use their powers. Resident Evil had a few of those flying kinds of zombies too.
Anyways what I want to say is, Pokemon-who-have-become-zombies-cannot-use-their-powers concept worked pretty well in Pokezombies. It was fun, challenging to fight, and at the same time, not very easy too. Plus we had a zombie gyarados thrashing around at one point. That had been fun.
How would i know. I mean you can't expect a zombie to fly a plane would you. You said it yourself, zombies don't have a brain so the only way to actually get from Sinnoh to johto is damn well swimming....... Thats the only option i got +_+