I added z-levels to the island so I could add caves and towers and eventually large trees. But it was really slow and I wasn't too happy with the direction it was moving things. The performance was worse, the code became bloated, and it didn't add anything fun or neat or new. So I'm going to revert this week's work and save z-levels for later.
I may get rid of elevation all together - I don't know. I'm not sure what it would add gameplay wise and this is starting to turn more into a simulation than a game. Sims are fine but I want a fun roguelike game, not a SimEarth wannabe or a lame Dwarf Fortress.
I think I'll focus on making it a playable game now. You know, add ways to suffer die.