PNG images, but I can't open them

[Davy Jones]

Just what I thought, these are encrypted and used for hiding the original pictures. Here are some bigger ones:

Everything from 100-999 kilobytes:
https://mega.nz/#!gY5EQB4L!mCFa8dlfnwqnm...kHJMkc8X9o
Size: 114,9MB
File extension: PNG

By the way and just if it helps:

Here is a encrypted file with the name 00020100.png, this one is from me:
https://www.file-upload.net/download-127...0.png.html

And now this is the same file, but from the internet, decrypted and therefore viewable. It was also named 00020100.png and is an actual file from the game:
https://i.imgur.com/0yGGWiz.png

Someone on the internet was able to decrypt the compression, I already messaged him but I'm not sure if he responds. Could you take a closer look how he possibly did it?