The 0.3.x versions were meant to focus on adding monsters - hence the recent water and fire caves - however as I was thinking about dark and light monsters I realized that a simple re-skinning of stone dungeons or rock caves wasn't going to cut it.
I always planned on adding a crystal themed dungeon as it's a core setting for the series, I hadn't really planned on doing this in the 0.3.x time frame but I was getting a bit bored of adding monster after monster.
To see these new caves you'll need to start a new game unfortunately, and they're only currently part of the final dungeon. Expect that to change as time goes on - this dungeon style will be the basis for light an dark themed dungeons as well as the main quest dungeons.
Changed files in this update