There isn't much good to be said for the Mercury Dungeon. There isn't much treasure, and while there is a good stock of Tri-Lithium, it's not easy to reach. This dungeon has very standard ladder setups, always alternating between the same two positions (a la Ultima I). Between this dungeon and Mercury's hostile surface, there isn't much reason to visit the planet.
The only real item of note is the bizarre wrapping in level 03. As far as I can tell, the wrap doesn't exist until you enter it from the lower right corner. After that, you can freely walk between the two ladders through the upper left/lower right corner. It's quite strange.
The only real item of note is the bizarre wrapping in level 03. As far as I can tell, the wrap doesn't exist until you enter it from the lower right corner. After that, you can freely walk between the two ladders through the upper left/lower right corner. It's quite strange.