That's pretty disappointing to hear. My first time through the game put it at "best ever" (or somewhere thereabouts) for me, but I don't think it's going to hold my attention to the same extent anymore. I find myself really just wanting more bite-sized platforming challenges.
My question would be: if you felt that way, why would not feeling the urge to get every single moon change that? If I only get 500 moons and stop playing I don't think I would feel any worse about the game.