I don’t know if this issue is fixed in the in-development version, but you should normalize all your filenames to lower-case.
Any RPG Maker MV/MZ game can be easily ported Mac/Linux/Android by simply swapping out the NW.js runtime for one built for the desired OS, EXCEPT that unlike Windows, other operating systems give a shit about case in filesystem paths.
This demo functions perfectly fine on Linux (and likely other platforms) but fails to properly load several assets because of case mismatches.
For example, the game trys to load www/img/layers/31_Лока_Фон.rpgmvp but fails because the real name of the file on disk www/img/layers/31_лока_фон.rpgmvp.
This works properly on Windows because it has a case-insensitive filesystem for some reason so those paths are identical as far as it’s concerned.
This is easily avoided by just always using lower-case letters in filenames, or at least enforcing some kind of consistent naming for files.
For those who want to bother, this game should work on other platforms if you have the patience to rename all the files to the case the engine expects.
The proper way to fix it however would be to normalize the filenames and release a new build so the game doesn’t ask for the wrong path in the first place.