It's funny, I think going in to Hurlers I was expecting something along the lines of, I dunno, La-Mulana, and what I got instead was a structure that's very uniquely FL - in that the complicating elements of the Discordance storyline are not convolution or specificity but a combination of opacity and opportunity cost.
I think it would have been an easy reach to, in a narrative-focused game, bow to the pressure to do a lot of traditional wordy puzzle design like lengthy riddles, coded messages, etc, that focused on the reading part of the experience and ignored the rest of what FL is. Or alternately to do an ARG-like sort of thing that insisted on trivia, background knowledge, or outside collaboration. Instead, Hurlers is really deeply embedded in what makes FL the game it is.
I think a lot of games have trouble leveraging opportunity cost, especially for failure, because in a relatively freeform game it's hard to create without like, aggressively telegraphing what the player should be doing in the process. Most games don't actively punish the player for using their basic verbs wrong - not even La-Mulana, generally! Which means they have to figure out far more obscure and specific ways to check the player's attempts at a brute-force. But because FL is built, fundamentally, around an action economy, the simple act of creating a fairly large space with a weird set of traversal conditions anchors the player heavily to their action limit and means that figuring out what's changing what, when, is is not free at all. It forces the player to pace their exploration and investigation out over realtime hours, days and weeks. You can't really focus down the discordance in a single push, and that helps heavily in reinforcing the other half of the equation, which is a masking of both progression methods and the conditions for said progression. FL's unique setup wherein quality names can be hidden, wherein story branches can be hidden, wherein repeating the same action can have different results, all lend themselves as fodder to creating an environment where, paired with a heavy opportunity cost, the player is as likely as not to flail confusedly - to repeat things fruitlessly, to manipulate conditions without understanding why, to experiment and fail - rather than making progress, especially if they aren't taking the time to meticulously note how all the storyline's effects work and are manipulated.
The result is something I really feel like you couldn't quite pull off anywhere other than FL. It's leveraging so many things that are so deeply baked into this weird game's structure, taking things that, in other circumstances, players would complain about or would be considered flaws, and turning them into narrative and gameplay design tools. It's genuinely kinda fascinating and just goes to show, I think, just how personalized good puzzle design has to be to the elements of the game in question. And perhaps, just as importantly, how building a really distinct tone can let you use elements of your game's design in ways that you wouldn't otherwise be able to get away with. Neat stuff.
I'm in the late parts of this story (no spoilers please!) and the other thing I'm appreciating is that this story is letting itself do things that Fallen London is usually a bit shy about.
Because actions are an economy - you get one action every ten minutes and can only bank so many - the game has to shy away from wasting the player's time in frustrating ways. Especially since one of the microtransactions, which goes back to close to the beginning, is buying a few extra actions. Wasting the player's time in a thoughtless way could look like the wrong thing, or just be upsetting.
Irem, and also the Hurlers, is in a space that's intentionally bizarre and confusing, and so both of them let themselves be obtuse in a way the rest of the game doesn't. It doesn't give you real hints to its structure, and instead lets you waste time exploring things while you try to understand the base ruleset of the area. It's breaking the rules the rest of Fallen London follows, and I love it.