Kingdom Hearts is renowned for its endearing but needlessly complex story, and apparently its eccentricities don’t stop there, extending even into its software design. As discovered by Reddit user PerhapsUnexpected, it appears that save files in Kingdom Hearts 2 Final Mix are stored inside a single PNG image. Seriously!
The internet sleuths found the strange 7MB image while digging through the files of the recently released Kingdom Hearts HD 1.5+2.5 ReMIX PC port. They were probably expecting to find a typical save file format like a .txt, but all they could find were two PNG images—one with Mickey Mouse ears called System Data and another with Sora's face called Save Data. Confused, they tried opening the Sora image with a hex editor and found what appears to be their save data embedded inside the PNG's metadata. Watch the discovery recorded by Perhaps below.
The whole thing is pretty bizarre. Notice that the image itself isn't hiding the data on its visual layer like some secret spy code. The save is buried within the image's metadata, basically a side storage area within the file that could theoretically hold any simple data. Open the file with a standard image viewer and all you'll see is Sora's face, but feed it into a program looking for the metadata and you'll find the ones and zeros within.
So, why go to all the trouble to pair saves with images? There's no immediately obvious advantage to this strategy beyond it being kinda neat. They certainly don't save space (if anything they slightly inflate the total file size). It's possible that Square Enix wants to make Kingdom Hearts saves easily shareable on social media (you can't upload a text file to Twitter, for instance). Except, as ResetEra user exodus points out, some image sharing services automatically strip parts of the metadata from files, which ruins the fun.
It's also possible that Square Enix just wanted to make save files a bit harder to replicate than your standard .txt, but I have to imagine there are better ways to accomplish that than PNGs. The console versions of Kingdom Hearts don't appear to store saves the same way, so this could be a measure to ensure the two platforms aren't compatible.
I've never heard of save files embedded in images before today, but apparently Spore was doing something similar back in 2008. User-created creatures in that game could be shared on an official website as PNGs, except the save portion isn't stored as separate metadata, it literally is the visual data. A couple of ResetEra users said some adult games also use the metadata strategy to share custom characters. Huh.
Is it cool? Absolutely. Completely unnecessary? Undeniably. But what else can be expected from a series with titles such as Kingdom Hearts 358/2 Days? Of course the series' debut on PC comes with its own weirdness. I wouldn't have it any other way.