Here is the new frozen rare worlds, the Rogue World! Having floated through the void for an unknown amount of time this dark planet can generally be found near black holes.
I made the choice not to have them as their own start systems for the sake of my own head canon for what can create a hyperplane, but I'm open to other ideas if people have them.
This and the Acid world will be part of an update I plan to have out in the next few days, along with a bunch of bug fixes/minor content.
We're already started a new cold rare planet, the Eyeball world, (a cold ocean tidally locked planet). I'll be posting about that as soon as it's done. After that is a custom Venus and then the start of three new base planets.