When is it time to stop playing a game? When you've beaten it, are playing it on a harder difficulty just to get some unlockable that you know will be disappointing, and every time another fifteen Black Spider Clan ninjas drop onto the screen your first thought is no longer "Bring it!", but "Ohhhh CRAP!" Seriously. The normal difficulty in Ninja Gaiden Black was hard, and occasionally cheap, but was rewarding more often than not. Hard is just CHEAP. The only way to beat it is to be just as cheap as the enemies, and even then it's a "one false move and you're hosed" kinda thing.
Time to get a new game before I need to buy a new controller.
music: Black Francis - Threshold Apprehension