If you need to keep the information on a server you then need the AJAX plugin to call a saving script on your server (that script is out of the scope of C2 and totally dependent on your server, coding language, etc...)
Simply pass the name, score, etc... through the AJAX call.
Be sure to look at the how do I FAQ to find out some examples of AJAX calls to a server, passing informations in the process.
Finally, if you want to get the infos as JSON, you likely want to first put them into an array and only pass the array.asJSON expression for that array.