Square Enix have been digging deep into their vaults the past few years, including several more restored gems announced at E3. They aim to make their whole back catalogue available digitally, but there's one big obstacle. As CEO Yosuke Matsuda admitted when talking to Game Informer "I'm embarrassed to admit it, but in some cases, we don't know where the code is anymore". It's a common story in the games industry, and one of the biggest obstacles to properly preserving games. When recovery efforts fail, some studios have had to cleverly work around their missing code.
While sad, it's not surprising that many games have gone missing, one way or another. The concept of games preservation is a relatively recent one, and as Matsuda admits: "It's very hard to find them sometimes, because back in the day you just made them and put them out there and you were done – you didn't think of how you were going to sell them down the road. Sometimes customers ask, 'Why haven't you released that [game] yet?' And the truth of the matter is it's because we don't know where it has gone."
There are plenty of tales of lost source code or beta builds turning up in strange places. Matsuda mentions they found and recovered the code for one game from the computer of a developer who had left the company. Perhaps this partially explains why it took so long for them to announce a Final Fantasy 8 remaster? Even Blizzard managed to lose their original StarCraft source code, only for it to be discovered by a fan, as reported by Gamasutra.
Sometimes, workarounds need to be done. The recent Blood: Fresh Supply re-release is reportedly based on reverse-engineering, as the final source code was unavailable. Square Enix's own Collection Of Mana on Switch (a bundle of Secret Of Mana games) includes the never-before-translated Seiken Densetsu 3, now known as Trials Of Mana. The surprising part is that people have found that the new SD3 translation is a fully functional SNES ROM, capable of running on original hardware. While just speculation, I wouldn't be surprised if Square edited the ROM directly, similar to an unofficial translation patch, in lieu of porting the game from its original code.
The only fly in the restoration ointment, at least as far as Square Enix goes, is a possible subscription service. Citing Bethesda's recent announcement of a streaming service, Matsuda suggested something similar was on the cards. "We still don't know if it would be a subscription service or an exclusive downloading service or what form it might take, but we do want to leverage our catalog". While I'm hoping to see Square's pre-merger back catalogue revived, I'd rather it not be via DRM-shackled launchers or broadcast with input lag.