Download won't launch for me, assuming I'm trying right - I'm just loading the index.html in a web browser.
Unzipping it with 7Zip or Windows' default zip tool does not change this. It gives me different errors when launched in Chrome and Firefox, but neither work.
Top line of the error in Firefox: DataManager.checkError@file:///C..../NEKO02400Web/js/rpg_managers.js:172:15 (Assuming this is not printing correctly, and is the same root cause as the Chrome one, as this location in rpg_managers.js is an error throw when it can't load a file)
I can't copy/paste them so only putting the top line here.
Top line of the error in Chrome:
Error: Failed to load: data/Map052.json