Thanks for the great game!
The game can’t be started under Linux. The reason is outdated nwjs. It would be good to publish the next releases with a newer version. Instructions are here: https://itch.io/blog/484532/how-to-update-nwjs-in-rpg-maker-mv-for-rpg-devs
I tried nw.js version v0.103.1 (latest) and I didn’t encounter any problems while playing.
For those who don’t want to wait, just run in the game directory:
wget -qO- https://dl.nwjs.io/v0.103.1/nwjs-v0.103.1-linux-x64.tar.gz | tar -xvz --strip-component 1
Of course, back up first and then try.