That is actually the part I wonder... with more and more prototypes of Sonic 2, we still can't seem to find any actual Dust Hill remnants. Just a name. Was it ever implemented in software beyond a slot and a name?
It isn't, but drx is aware of a "post-NA" build which is very similar to the NA build, except that it also has Mystic Cave in it. I don't know exactly how much later it is than the NA build, but I imagine it can't be too much older.
Now, if we see a version of the game with title cards enabled as in the final with Mystic Cave listed as DHZ in that title card, that might be enough evidence to sway me to the idea that MCZ was intended to be called DHZ. Still, it IS odd that there isn't any DHZ art anywhere.
Honestly, I agree with this. Dust Hill == Desert Level, but Dust Hill != a playable level. Can anyone honestly say otherwise at this point?
I believe that there is more DHZ art in existence somewhere other than just a magazine shot. I don't know why, I just have that feeling.
The question I have, that would probably go a distance towards reconstructing the process, is do we have any kind of build dates on the NA and Wai protos? I know we can narrow things down somewhat based on when said prototypes were demonstrated in cartridge form, as one was around during the taping of a television show, and the other was claimed to have been stolen from a trade show (though no proof that the Wai was the stolen one has surfaced, at least to my knowledge). But Protos 4-8 all have dates assigned to them, which I can only guess is when they were compiled (is this correct, drx?). Going on the assumption that the above is correct, given that we have a total of 5 prototypes with only 11 days between them, why, then, do we not have any that fit between NA/Wai, or Wai/Proto4, with the several months they had to work with? I'm thinking the only way we'll really get answers is to find and dump more protos, especially that Gold Guide one...
Because those prototypes in the soa archive were produced in the beta-phase for testing - the game was already "completed" (feature-closed, you name it) and bugfixing was the only thing left. Before this point it wasn't that important to produce "public" builds other than for magazine previews and events, so we are already lucky to have two of them.