I will admit that one of the reasons I love Volcano Forts is the nostalgia for 2D. I don't want to go back to 2D (things are better now!) but the way lava works is just so cool. Plus unlimited glass forges are just so excellent.
Underground waterfalls were awesome, I have since started making underground waterfalls landscaped through my caverns from the aquifer, to a drain on the other side. Lots of pretty. Lots of fun! Fiery forgotten beasts beware!
I
am interested in when and whether we start getting digging enemies. I expect there will be ways of redesigning forts to not allow a digging enemy much success. Perhaps living under the first cavern layer could be the only way, if all diggers enter the map on the surface. Perhaps built structures wouldn't be diggable, meaning you have to "strongbox" your fort with manufactured walls, and build a real
fortish sort of fort. Really, though, we've gone through just so many different changes in Dwarf Fortress that I don't think this will harm the game or break the game, it will just result in a different playstyle, as all the changes have so far. I mean, I'm now walling my artifacts into strongrooms if I don't have the ability to surround their pedestal with chained wardogs. Perhaps in a future fort, I will be building a fort on stilts above a pool of magma (or a heavy aquifer) to prevent digging artifact stealers. Who knows? I am sure of one thing: I will still be enjoying and playing the game.
(Unless the game is reduced image tilesets instead of ascii, of course, hahahaha

(yes, I am aware and delighted that I can keep using text instead of images!))