For the Love of Salt: A Prelude was a game I made to show how narrative difficulty and game difficulty can be irrevocably intertwined. I feel like it was a failure in this respect, but it was the first digital game that I managed to finish since Neighbors. I wrote a whole post on this game. In short, the game was showing off two techniques for tying the narrative to the game difficulty. One was spatial: going to a new area provided more of the narrative, but also made the game harder. The other was mechanical: the same resource could be used to reveal more narrative content, or to defeat enemies.
You can get the game here for PC.