Just read a cool analysis of the appeal of LOST in terms of CRPGs. The treadmill aspect of long running series or games can be done well, as in WOW where in the early levels there are parts of the world where you clearly can’t stay (and which you sometimes have to dash through to get to areas you can thrive (see: the trip from Menethil Harbour to Iron Forge if you are a young Night Elf). It can also be done poorly as in Oblivion where common bandits suddenly started acquiring ELDRICH ARTIFACTES as I gained in levels.

Maintaining the treadmill of a relatively even difficulty curve while also giving a sense of progress is a special kind of art form in and of itself. Even WOW which is overall masterful lost me to the perpetual grind when I realize just how far from level 60 I was and how little marginal value to my life those final 20 levels would have been compared to playing a different game entirely.