The game has been released today.
https://store.steampowered.com/app/955050/Bright_Memory/Seems built with UE4.23. Pak files are encrypted.
The game was made by a
single person, he dedicated personal time and skills to it, and sells for almost no money - It's price (for Russia) is less than $2. So I'd strongly advise to purchase the game instead of begging for "someone upload pak files".
The game takes 7.7Gb of the disk space. 4.3Gb takes the game itself, and 3.4Gb - RTX tech demo (which is quite short, but takes so much space).