quote:
Can we do this? I mean, is it possible to introduce a new type of planet with special characteristics AND that always contains ruins?
Yes and no.
In theory, something like this can be done in the Map Editor, but 1.49 has a bug that doesn't recognize ruins on maps that have been saved in the Map Editor. (I've reported this to MM.)
1.49 does recognize ruins on maps generated in 1.49 itself, so there might be a way to implement something similar via the Data files, but I don't know how to do it.