So what I need to do is to assign every player a unique name, rank and update their scores every 10 seconds or something and display their rank among other currently playing on the screen. Its not exactly multiplayer. They will be playing at the same time but the only information I need from them is their score since the 30 minute session has started.
I am not looking for a global leaderboard. Just for the 30 minutes. Whats the best way to do this?