(Spoilers)
I'm curious if there is more than one ending.
After beating the game, a new NPC appears in the King's Doorway. They have a few different dialogue routes you can go through but it otherwise doesn't appear to affect anything.
Likewise, going through all of the No Go Door paths doesn't appear to affect anything either.
It just feels like there should be more... Maybe I'm simply missing something? Or maybe that's truly all there is.
In any case, this was a worthwhile and interesting experience.