I think I understand people's problem with the Wily Stages in this game after playing the difficult mode. The dragon can kill you in one hit, the blocks do 1/3 of damage to your life-bar, and the Boobeam trap is a bit more annoying (can't put my finger on it, but there has to be something).
The robot master stages are excellent though. Might need to replay of the normal mode to see if its as good as I remember.
Since its basically the same game, I wont add a star rating.