Last year, the hacking geniuses over at Sonic Retro managed to get their hands on a super rare Autodemo for Sonic Adventure, and inside of it, found the files for the original layout of Windy Valley, which was scrapped at the last minute for the version we have today. The sad thing was, though, nothing was playable at that time.
Since that find, a large group of programmers and hackers at Retro have been working to make this gem playable and now, little over a year later, they’ve finally managed to make it happen for those who own the original PC version of Sonic Adventure DX. And it’s not just a texture hack either, everything from the original demos has been recreated, from the layouts to the camera angles. After so many years of wondering and waiting, finally getting to play this version of the level is a real treat for longtime fans, on par with getting to play the full version of Hidden Palace Zone in Sonic 2 iOS.
The hack and source materials are available to download here, along with instructions on how to use it, but again, keep in mind that this is just for the original 2004 PC release of SADX, not the Steam release. It remains to be seen if they’ll make a mod for that version.
Source: Sonic Retro