I prefer long story, and hard level

I'm not sure this kind of game should be build to be played at different level of difficulty. In my opinion, rewards should be very similar whatever the level.
Some people prefer shord and easy gameplay to hit ending reward quickly.
Some other prefer spend lot of time searching thought story, and found ending reward more "rewarding" if the way to hit it is hard.
Difference between reward's level should be some extra intermediate picture for exemple, but not a full different ending.
For exemple, day dreaming should be available only at medium or hard level.
Most of time, people who like to play in easy mode, doesn't want to find all "bonus" in the game.
That allow to save one of most precious ressource when you write game: Time !