Hi guys, I don't know if this has been discussed before, but I haven't noticed it before. Found it by accident when retroarch scanned my library and booted the wrong file. This rom is listed as a 'bad dump' of Sonic 3, presumably listed as final. However a lot of Sonic's sprites are from Sonic 2? This isn't listed as a hack or a beta. Where did this rom come from? The one in question is: Sonic The Hedgehog 3 (U) [b3].gen, and the filedate is listed 29/10/2000 !
It's probably a mislabeled hack. GoodTools sets are by no means perfect I just gave it a quick test, and though I didn't play the whole thing or give it anything resembling an in-depth examination, it didn't look like a proto or anything. Everything I saw other than a few of Sonic's sprites was, as far as I could tell, just the final game. I would be very surprised if this turned out to be a proto sitting under our noses for decades.
Stranger things have happened, but I wasn't sure either way. I thought I'd better bring it up for someone to compare as I don't have the tools or experience to do a binary diff.
I checked out the ROM myself. I was greeted with an "incorrect checksum" message and Sonic 2 sprites that are a bit different from the actual Sonic 2 sprites used in the prototype. Yeah, it's just a hack.
Did the proto sonic 2 sprites in sonic 3 have a modified sprite set to use sonic 3s pallette similiar to how tails is?
Nah, far as I can tell, even Tails is unmodified aside from being forced into a new palette: only true difference is Sonic loses a middle shade. http://info.sonicretro.org/Sonic_the_Hedgehog_3/Development#Prototype_screenshots