To explain it before I show the pictures, you have an area where there is no ice, where there should be ice, and just water going straight down to the ocean of water. Then, you have your randomly generated dungeon (at least, I believe Mic has them randomly generated.) Some rooms are filled with water, some rooms don't have water. In the air-less rooms you could expect sea creatures more often than that drowning evolved zombie. In so air filled rooms, expect just evolved monsters. What's interesting with this dungeon is that some rooms have tunnels going up and down that you have to nerdpole or swim up, or jump down to get to more areas.
I'm messing around with the boss room still, and I'm making my dungeon example pretty small just to help explain it.