The theme for the sci-fi set I've been making. The top left theme is for all overworld levels. The metals in this one actually have a more reddish tint to them. You can also see the trees are now poles and the bushes are...things. Sci-fi things. The top right is the underground levels, which are meant to be the vats where they store that green liquid. Not sure what the liquid is but boy do they have a lot of it. The bottom left is the castles, which have all kinds of sci-fi lights and shit in the walls. The bottom right is the underwater stages. It actually looks subtly different from the overworld, but is pretty similar.