How long is Smoky Skies? How big is the map?
I'm about to finish my first game on it. You start with 2 extra settlers but then you really can't have more cities than three (settlers cost like 50 turns/2000 gold or something ridiculous like that). So the map's pretty small, there's 5 civs, and they'll have 3 cities unless they heavily invest into another settler (I saw an AI do this in my game but it seems like a terrible plan). Of course, you can capture other civs though.
The buildings that you end up creating are all very powerful. There's a lot of buildings that boost two things at once, like +science/gold, culture/happiness, etc. There are also "national wonder prerequisite" buildings and when you build those, you can build a national wonder building (for example there's a building that's basically Ironworks but under a different name). This all makes your cities pretty powerful if you get a decent start.
You're generally using landships as your melee units, there's artillery, there's flyers which are like fighters, and there's airships. Landships start at 60 strength but have 2 upgrades that turn them into 85 strength monsters called Land Leviathans that are essentially modern armors. You need a resource for them but I found that city-states often have them. When I captured my neighbor I had a line of the modern armor units with artillery behind with some flyers intercepting enemy flyers. I didn't use airships much but they're pretty fast and are decent anti-personnel, especially against landships (100% bonus and that can be upgraded)
You have 5 social policy trees. A lot of them are very similar to base game SPs. There's one that's essentially Honor/Autocracy, one that's Commerce, one that's Piety, one that's Order, and one that's sorta a mix of Tradition/Freedom (with the +2 science on specialists policy too)
Anyway I'm just passing turn 100 and will probably have the game won before 120. I'm sure better players can pull off wins around the ~80 mark.
There's a lot of espionage here. The tech tree kinda branches toward your intended playstyle but if you're trying to play culture you can also steal some military techs that you probably wouldn't have otherwise. The enemy will do that too. Even with police stations built and spies running surveillance in my cities I still got my techs stolen more often than not.
And of course there's 5 titles and the game ends when you get 3 of them. One's having the most social policies, one's for having the most gold generated through the game, one's for having the most landships/airships built, one's for building the most world/national wonders (there aren't new world wonders for the scenario, they're base wonders), and then there's the most productive city. You have to unlock the titles through the tech tree. Once they're unlocked, every 5 turns, there will be a briefing on who holds the lead on each title. Once you have 3 titles on each of these 5 turn intervals, you win the scenario.
It's an interesting scenario and it's fun to play with new units and buildings, but I personally feel this scenario is not too replayable. You can change the map to any map type which is nice for what it's worth. But it's essentially a modern war scenario where you can only have a few cities and the units just look different and have different names.
Edit- Won at turn 108. Definitely could've easily won before 100; probably before 90 frankly if I focused on my victory better.