I would have to disagree. At least not harder than any other classic song out there. Most, if not all classic game music are just loops of a 1-2 minute long song, and the remixers on here have done amazing work by using their creativity to extend the tracks and still make it sound incredible.
For example, Dhsu and Black Omen's remix of Mario RPG's "Sad Song". A 30 second track that they were able to turn into a 4.5 minute masterpiece. I believe the same can be done with Megaman's Protoman theme, the remixers on here have amazing talent.