Found a copy here: http://www.eldritchdark.com/writings/short-stories/155/a-night-in-maln%C3%A9ant and someone reading it here: https://pietersender.wordpress.com/2020/04/01/readings-a-night-in-malneant/ [about 16 minutes[.
The first thing I was reminded of when Glenn and Brandon were discussing the description of Malneant was the descriptions of the floating city in Moorcock's Elric stories.
I think the river may be Lethe, the river of forgetfulness or oblivion. That's what the narrator is seeking in the first few paragraphs. It seems to me that this whole vignette is taking place in the narrator's head: everything not near him is shrouded in mist or shadow. He has no perception of it because it's not important to him. "And everything about me, the tall and misty houses, the dark, indefinite streets, the rare and wraith-like figures, became as if part of the obscure confusion and fear and bafflement of a nightmare."
To move this from a vignette to a story (with plot and action), it could be turned into a retelling of Orpheus and Eurydice. The narrator could spend the night trying to rescue Lady Mariel from the bier. He could think of it as a second chance to not be a terrible boyfriend.
Also, you were asking about alternate media for this. I think the exploration game/dungeon crawl would be good, but I really want to rewrite the lyrics of One Night in Bangkok to make it A Night in Malneant.
Malneant, funeral setting
And the walker don't know, he's just forgetting
The toll of the bells is always ringing
Town with nothing but streets misleading
A night in Malneant and it's just oblivion
The inns are full and the streets are dim
You'll find a bier in every dark cathedral
And if you're lucky, it's not Marial
I can't forget her death was because of me
Like Glen, I read fiction to find the right atmosphere and mood and imagery (and also psychological and/or philosophical depth) and am not so much interested in plots, although I can be annoyed by implausible plots. This story is exactly the kind of story I love, so I really enjoyed it. It's also why I like well written weird fiction and new weird with the right amount of eeriness and dreaminess.
I agree with ktvician that the story takes place in the character's head. It seems to me to be a kind of picture of his inner struggle. Although it seems that he does not want to take responsibility for his actions and seeks oblivion, Malnéant still struck me as a purgatory. The prolonged wandering and inability to rest may be his self-declared punishment, because deep down he knows he must be accountable for his deeds.
I also agree that the end of the story is a bit meager. It is as if C.A.S. didn't know how to end it right, but I still love the story.
Like Brandon, I think this story would be great if it were made into a point-and-click adventure. I really Loved the weird p.a.c.-game 'What Remains of Edith Finch', a very good example of choosing the best medium for a story/vignette. (View a trailer here: https://www.youtube.com/watch?v=4mrx1G26GTQ )
I think you just wrote our new intro music! Listen for it next year!
Those adapted lyrics are great. As is your suggestion to give the story an orpheus/euridicy plot outline to it. I think the website you posted is the one where I read the story. It's the full text.