I wonder if you could generate many maps that are all very similar to each other. This way you could create a planetary look and feel and each time you jump in, it's a slightly different map. Eg: Sometimes there is a river, but there are always big shiny green mountains, and there are lots of purple lakes. There are no trees.
With some tweaking, yes this is achievable. However, someone would have to create planet templates for every planet. A planet template would need to include the height map template, a list of stratum, the lighting parameters, the water parameters, and the list of possible props.
I'm already doing that for the stratum and props, and it wouldn't be a big change to add water and lighting.
The real challenge would be in designing the height map templates. Ideally, there would be one for each planet, and it would be meaningfully distinct from the other height map templates. Obviously, we could re-use some and just change the other variables, but that's still a lot of new height map templates that need to be created.
In order to do this "on the fly" though, the map generator will need to generate a playable and "mostly" balanced map every time. I don't have it at that point yet (not saying it isn't doable, just that it's not there yet).
I do appreciate the suggestions. Unfortunately, it'll take a while to get these types of improvements in the map generator if I'm the only one working on it.