The Jewels of Aptor (Project Gutenberg, LibriVox) is not a long story. But it took me ages to read (that is, about a month). Which isn't because I didn't like it, it did. It simply wasn't my thing, and also I was kinda depressed so reading wasn't my thing anyway. Much less thinky reading.
It's not terribly thinky. It is perfectly possible to follow the plot without too much thinking. But I feel like a bunch of stuff went over my head because I didn't pay enough attention.
It starts as an adventurey "journey to an unknown land" type thing, and while I was unpleasantly reminded of a lecture about utopian fiction that I never did all the reading for because I probably didn't have the energy or something, I got over that. The words were very picture-makey for me and the characters are hecking cuties. And also, when more is revealed, it takes a somewhat different direction.
There's… a lot of stuff going on about "good" and "evil" and how these categories are a bit too simplistic usually, and about understanding things that seem simple from further away, and a bunch of other things that I can't remember now, which doesn't matter much, because I really can't do this story justice.
I read it, but just barely. Anyway, I liked what I read.