Thanks for your answer Kirill.
The window.open works well for the browser, thanks, but i plan to make a version of my game for windows, mac and linux. What commands need to be used for exporting to a pc (i'm using web2executable, so nw.js)? Because on a windows export, it open the url in a new restricted window, not in your browser. And will it be another command for android?
"To display a variable in the text, you must use the variable name in angle brackets <variable_name>. (I checked, I probably broke this feature, I will fix it in the next release)"
Do you have a screen or example because i really don't see what you meant? Even if the feature is broken, at least i will know how to do it when the next release is online.
And i found another bug (sorry). On my main screen, when i click on "load" button, if there was no previous save game, buttons disappear. And of course a new player doesn't have a previous save game...
Before clicking:
After clicking on load button: