It's possible that your games are automatically deleted if you uninstall the game, but you can install them back through the manager. The credits won't disappear because they're tied to your account. You can log in on how many computers you have and the credits will be displayed into the Big Fish Games: Game Manager interface after you log in.
I've just installed the application, logged with a username, downloaded a game and uninstalled, then repeated the procedure and it was just like I said above.
