This review is spot on.
In the old days of NES and Super NES, there were numerous games that I enjoyed, but never could complete because of their ridiculously difficult requirements.
Conquest of the Crystal Palace, Mega Man, Zelda II, Siecross, Section Z, etc, etc
The only Mega Man game I've ever sat down with and tried to master was Mega Man X. I got all the way to the end boss, Sigma and I believe I beat the game after grueling hours of trial and error.
Mega Man games specifically, are hard because they aren't very long. There are only 8 bosses or so, and the game can be beaten by someone who masters it in less than one sitting - possibly two. Back in the 80's, games tended to be like this: examples include mostly Capcom and Konami games.
But nowadays, if I buy a game I want it to be more updated for play on a next generation system, rather than being completely retro. I'd accept the retro graphics of Mega Man 9 on Nintendo DS or gameboy SP, but if I'd buy a 2D game it better have 3D graphics - a perfect example is CONTRA: Shattered Soldier or Gradius V. It is difficult to change the formula of a retro game, but it is possible to do and be successful...Nintendo for instance has been selling a shitload of retro games repacked to look new: New Super Mario Bros, Zelda (anything) etc.
From this review, I can infer that this game is for hardcore Mega Man fans only.