@NeonJelly
I wish i read your comment earlier, just sat waiting for a 1000x1000 map generate, took 45 minutes on a high end cpu! xD Holy shit this is a big wrecked city.

This happened the generated map before aswell, but i was unsure if i was just unlucky then.

So yes i am confirming your bug, get the exact same result in 1.6.

For anyone wondering, I gave this a try, and while I'm not sure about other maps, it makes your starting map just like the screenshots, and if you use a start with a building (i.e. I used one where you start with a small gravship on the map) it will just delete most of the building. It also happened to spawn a bunch of jade walls for me. It doesn't seem like it's an isolated map 'type', but just majorly overrides map generation.

@CrackaJack I dont know, havent tested it that much

sooo this adds ruined cities as map to visit? sounds good, but increasing ore generation and such, is that optional? or only on the ruined cities? or does this change general map generation to have ruined city prefabs in it?