An unreleased NES game based on the movie Days Of Thunder was just re-created and released. This was accomplished by reconstructing data found across several 5.25″ floppy disks. Making things even more complicated was the fact that the information on these 21 disks were backups of 4 separate hard drive partitions, in a proprietary format generated by PC Tools 5.1. That means not only did the team have to deal with all the nuances of old magnetic media like bad sectors and ancient FAT12 filesystems, but they also had to get these backups restored with old software and decrypt them!
Even after getting the data from the disks, there wasn’t just a rom file lying around; They had to manually search through all the files to find the code and artwork, combine them together and compile the game. It’s not complete, but playable and you compile it yourself if you’d like.
The full story is a really awesome one that any old-school computer nerd would really enjoy and appreciate. Please check it out here: https://gamehistory.org/days-of-thunder-nes-unreleased/
Reconstructing a lost NES game from 30-year-old source code disks