I'm currently testing how suited the tile set is for 3D dungeons. There are some problems, for example the tops and bottoms of the dirt walls don't fit and the claimed walls have some z-fighting issues (however, they can be stacked easily), but I think we should consider making the game truly 3D. Using voxels for the different terrain elements would probably solve some problems, and we could still use meshes for the claimed walls and rooms (as The Ancient Goat suggested some time ago). I have no idea how difficult that would be to implement for a programmer, though.
Let's brainstorm!