One thing that I've been thinking about regarding Sunless Sea, having now gotten deep in FL's systems, is how they translated the kind of cost-benefit analysis that the limited actions create. Like, in FL, there's lots of things you can do easily to get small resources with no risk, but because they cost actions, it feels like a waste to do that. For an example even closer to SSea (though I'm not sure if it was added to the game before or after SSea), I can give some gifts to tigers in London in exchange for tribute, then sail to the court of the wakeful eye in Port Carnelian and exchange that tribute for more valuable goods. But it takes 8 actions to zail there, so I don't want to go until I've built up enough tribute to be worth it, that's over an hour of my real life waiting for actions to refresh. And, more importantly, I could be do other things with those actions that might be generating money faster (I genuinely love how much the wiki has analyzed this, most repeatable grinds will have noted their expected "Echoes per Action").
In Sunless Sea, there's tons of those trade loops, obviously that's a big part of the game, but if you could just zail there and back it would be a bit tedious but efficient. So instead of just costing time, it also costs fuel, even if you upgrade your ship's speed the fuel cost will usually rise as well, so instead of echoes per action, it's more like echoes per fuel (though also, per supplies, which does become much more efficient with time but also scales with crew... etc, obviously the game totally about zailing will make it more complicated than the game about putting around London where zailing is an abstract activity).
And the "something awaits you" quality in SSea, which I found a confusing abstraction when I played it, makes more sense to me coming from FL. Fallen London has "Airs of London" as a randomizer quality, some locations will give you different options based on the value from 1-100, ie if you go to steal stuff in Spite, certain targets may only be available when Airs is 1-25, others at 26-50, etc. Airs gets randomized whenever you take an action that's dependent on it (and some other actions), so it always costs one Action to reroll and see new options (and if none of the current options are useful, you may even leave and go somewhere else in London to pick something and then come back to check what's available now). SAY serves the same purpose in SSea, but because just picking an option at the port doesn't cost anything, having it immediately reroll would be broken. Instead, it uses "spend resources zailing" as your cost for taking opportunities, so naturally, once you take any SAY option, you have to go zail around at zee for a while to get a new roll.
I feel like I should be wrapping up this long comment with some kind of conclusion, but, idk. I just think it's neat.
