I have put together a site which will become the hub for several browser based games that I will run. I would like to allow the players to create one login account on the hub site, which could then be used at each of the games. I don't think this will be a problem, as long as each player signs up through the hub (which they will). Each game would pull info from the drupal DB and compare what it pulls with what it expects, piece of cake.

However, I would also like several achievements from each game to be viewable on the players profile. I am still new to drupal, and am unsure on what would be the easiest way to go about this. I can think of ways to go about it, but I would like to maintain the modularity of drupal so as not to break anything. There is additional information that I would like to share amongst the databases, but this is the most vital. Any advice pointing me in the right direction of where to start would be appreciated.
Thank you in advance,
~Stray