> ...n-body simulation and non-symmetric gravity fields...

I want to agree with everything said here, and add that the KSP mod ecosystem is no joke. The few things mentioned here barely scratch the surface.

As a point of comparison: I'm aware of and long involved with the Minecraft community, and it is huge and excellent. While the total amount of mod material is likely greater for Minecraft compared to KSP, I'm comfortable saying that the mods in KSP are deeper and wider in scope.