Thanks to an article @Knightsaber showed me from yesterday, we have some more details on the second layer to the gameplay area, making it possible to find alternate routes to and from locations and even hidden areas!
In addition, it sounds like there are more NPC’s this time to run into (randomly) that will, like the Shopkeeper, remember things you’ve done (or didn’t do) as well as some quests/events that can play out. The entire thing sounds very cool, with lots and lots of additional depth over the first game. I wish we had some GDC gameplay to show this off, but maybe that’s coming yet.
Since I created the thread, way back when, some quotes from Derek Yu, the creator:
My opinion about sequels is that they are extensions of the previous games, so I want fans of Spelunky 1 to jump in and feel like they’re playing a continuation, both storywise and mechanically.
We’ve also added liquid physics that are really fun to play with – combined with the destructible terrain you get things like dynamic water or lavafalls that you have to deal with on each run. The world breathes more. And then there’s all the expected new areas, items, monsters, and traps.
I’m still very much thinking about new players, though. But my philosophy has always been to attract new players by making the world more interesting and inviting instead of focusing on tutorials and things like that.
Source - https://blog.us.playstation.com/2018/08/29/first-look-spelunky-2-gameplay-mossmouth-interview/
It’s still supposed to come in 2019 and with it being shown at GDC this week, I hope we get more coverage here shortly.