I think if I Can through Navigation Bar bakc HomePage it will be OK.
Where would this big link ideally be?
Maybe to the right of the current CodeCombat logo, and it would say something like “Main Site” or “Back to the Game” or “codecombat.com”?
Oh yes, this would be handy indeed
Maybe even make the current code combat logo go to the main set, and have some button that says “back to forum index” to go back to the index.