Master difficulty were your choices in skills will define your game for you.
Light armour at the beginning is a death sentence but higher levels and being a master in it is very useful.
Two handed is likely to get you killed very quickly
Block is actually useful.
Duel wielding blades is another way to get yourself killed.
If you don't use restoration you're going to die very fast.
And you'd should specialise in sneak, and at the same time you shouldn't...
And finally perks define whether or not you're going to survive the coming dragon battle.

So yeah it's a fun mode to play on.