NOTEAdditional notes, this tutorial is very old and maybe not working for now, because official client is available on official website.
here I will show you how to install and play one of the games that are currently being played by my friends or myself. Call it “Mahjong Soul” but on desktop like Princess Connect Re: Dive or another Anime Games (Granblue Fantasy).
What do you need to run this? Yes, you need software called NodeJs, so you can download via this link 
Install as usual (because here I have installed it, so I just skip it). Download the repository via the following link and extract it anywhere. 
After extracting all the files, run a terminal windows or cmd in the folder like this. 
so type command line on cmd npm install like this and just wait untill process done. 
when finished for the installation, you just type npm start to start game 
tadaa~ you can enjoy the game without open your browser 
How to change URL from EN Server to Japanese or CN Server? Simply, just edit Index.html. Open any text editor and edit src to https://game.mahjongsoul.com/ for Japanese and China Version https://www.majsoul.com/1/ 