^ I like it.
I imagine lava all over the place would get a bit annoying, though. On one world I started, on my first deep mining expedition, I was exploring a cave, and walked past a lava stream. Shortly thereafter, I was startled by a zombie, and while doing a panicky run backwards to give myself time to get out my sword, I ran right into the lava and burned to death. Lost all of the stuff I mined.