What should we call the moment when a game loses it's immersion and becomes simply a game?

Case in point: in Skyrim i'm standing at the blacksmith in Solitude. I look around and its gorgeous. There is so much detail in every corner, from the stack of iron ignots on a table to the blacksmith's bed inside his shop. But none of that matters to me after awhile as i'm power-leveling my skills pumping out iron daggers. I just rush from place to place and watch the numbers rise. What is it when we lose this immersion and begin to focus on the gameplay mechanics? It's something Peter Molyenoux always tried to capture. At some point we stop caring about the graphics, enviroment, ect.and just focus on winning, leveling up, or getting all the achievments. It's interesting... at some point it may as well be blocks and squares making up everything since all we want is to advance.