I came in here half expecting people to be demanding disc swapping being added to make the game more "challenging".

And I'm sad no one has mentioned MSG1 and MGS4. In the first Metal Gear Solid, there was a door you walked through which prompted the "please change disk" message. When you visit the same facility in MGS4 and walk through the door, Otacon gives you the same message, to which Snake reminds him they are using Blueray Discs, triggering a lengthy conversation about the advancement of technology.