A friend of mine and myself actually had an OoT challenge where we skipped every heart container and beat the game using only 3 hearts. The rules were that if you died you must either hit save and continue (so it would count your death on your file) or start the whole game over. While it did provide a few moments of panic here and there, the competition was bust in the end as we tied with zero deaths.
I think with nintendo games, there has always been difficulty to be found. Not necessarily going as far as skipping hearts, but usually there are optional side quests and things of that nature to test you. TP had the cave of ordeals, for instance. However, while i do enjoy and appreciate these little extras, I deffinately think that the main quest could be more difficult. The thing that ticks me off most about bosses isn't that they die in three hits, it's that the three hits are often delivered swiftly and one immediately after the other. The window in which you're able the hit most these bosses it too huge, and after they're hit, they often open themselves up to be hit again almost immediately. Sometimes I kill a boss without ever finding out what attacks the boss even has. The water temple boss in TP for instance never touched me, granted that battle was epic and fun, but I still to this day don't even know if that boss even has an attack...... Sorry I let that get away from me a little.
And to GP: The last time I played a difficult mario platformer was in sunshine when you enter those warp zones where you lose your pack.
At least metroid has always been a haven for true difficulty.