Launch "Light and Shadow - Doppelganger" using JoiPlay on Android:
1. You need the latest version of the game (currently 1.22). Personally, I use a purchased steam version patched through the Hanabi Games installer (1.22E).
2. When trying to run the game through JoiPlay, it should throw an error "process.memoryUsage() is not a function" or something like that. As far as I understand, the error occurs because this function is designed exclusively for the computer (maybe even only for Windows), but we do not care about that. The main thing is how to fix it.
3. After getting the error, we close the game, open Total Commander (or any other file manager that will give us the ability to edit any text files). We go to the game folder, and then to "www/js/plugins/BY_MainMenu.js" (the folder "js" should appear after JoiPlay "processes" the game. Previously, it simply does not exist there).
4. In the file "BY_MainMenu.js" we use the search to find the function "checkMemory", and then change the value of the variable "var AllMemoryUse" to any number less than 2000 (because this is the value set as a limiter for notification of memory overflow). I set it to 1000, but it doesn't really matter. You can write 69, or 228, or 666, or 1337..... Heh.
5. Profit! Save the changes to the file and you can run the game.
So, these actions disable the RAM check crutch built into the game. It was added solely because of the crooked hands of the developers, who could not do a RAM cleanup from cache and garbage when opening the menu. Including for saves. Yes, the developers couldn't fix one problem, so they added another. Classic.
I've also attached screenshots below for clarity. I hope this guide will help someone. And I'm going to finally play this game on my phone.... Although some visual bugs are present, but even so, it's an acceptable compromise. Good luck with the game!