I understand what you're saying but I just don't think it works like that for me personally. I've completed both easy and hard games and this is how hard games went for me:

Wow what a fun game!
Yeah I really like this!
Oh a hard part. I'll keep trying
Okay this is really frustrating, let's spend a few days preparing, grinding, getting equipment, etc
Okay this is still hard but I can get through
Okay I got through that hard part. Ugh. There's going to be an even harder part coming up isn't there?
Oh this is fun
Ah poo I'm probably getting to another hard boss soon. Oh man not this again.
Okay got through that one too. Ugh I hate these boss fights.
Oh yay this is a fun part.
Oh not another boss fight please please please
It's another boss fight. Ughhh I'll do it tomorrow
I don't want to do it today, I'll do it tomorrow
I guess I have to now to see what happens.
*fast forward*
Okay that was fun but I don't think I'll play again. It was just too much work

easy games:
Oh this is fun!
Oh yay I'm liking this!
Oh a boss fight. Oh that wasn't so bad!
I can't wait to see what happens next, etc etc
fast forward
Wow that was fun, I'll probably play that again!

I dunno, just personal taste I guess. Different things work for different people