With Sonic 2, I think it's safe to say there's only one meaningful prototype left to find (which I assume must be "Beta 3"). There'll have been a million different internal builds, but only a small handful of versions sent out to the public, whether that be trade shows, magazines, videos, etc. For the record, "Beta 3" would probably be the one with the more complete proto Casino Night, final running animations in Hidden Palace, etc. We have "Beta 1" (nick arcade), "2" (Simon Wai) and versions after 3. The reason there won't be many out there I imagine is quite simple - you have to do a bit of testing and quality control to make sure the Mega Drive doesn't explode during the demonstration. With internal builds, nobody cares. It is mere luck that drx found an archive full of them - I don't think there's much chance in finding any more. With Sonic 1 it will likely be a similar story. There'll be roughly three or four different builds out there and this really early version will be one of them. So http://info.sonicretro.org/File:GHZ-DarkBG.jpg - "Beta 1" (seven layers of scrolling GHZ demo) http://info.sonicretro.org/File:GHZ-CES91-1.jpg - "Beta 2" (debug coordinates in bottom right, different GHZ layout) http://info.sonicretro.org/File:GHZ-Ball.jpg - " Beta 3" (mostly final GHZ but with balls and purple flowers) Versions between "Beta 1" and "Beta 2" will have existed once, but I think the chances of finding them are ridiculously slim. You'd have to travel back twenty years and raid Sonic Team's archives. You could compare it to say, a web browser. In 2030 people decide they want to dig up old versions of Firefox - they can find the final versions and the beta ones, but nobody gave a damn about the nightly builds so it's almost impossible for them to find the 12 February 2008 nighty build or whatever. Exactly the same situation here - you're only likely to find major milestones. So though it's true that the welcome sign might have changed... I don't think we're ever likely to wind up with a "slightly different" build to one of the above three. It's too unlikely. Almost every Mega Drive prototype found has appeared to have been identical to one seen in a magazine before release.