I have already suggested weather systems for improved climate mode for rocky planets. The simulation of storms, tornadoes, hurricanes, and lightning would be amazing to simulate in Universe Sandbox. The sound of lightning storms would need to be simulated both physically and also by sound. That is the sound of lighting when lightning bolts clashes into each other.
Volcanic eruptions are also another great feature to simulate lava pools and rivers, plus growing and disappearing volcanoes must be simulated with time steps as well. That is something that Universe Sandbox absolutely needs to have as a new feature for rocky planet. When volcanoes erupt under water, Universe Sandbox must have suitable physics that can simulate the growth of underwater formations growing and cracks appearing when magma leaks out from those growing cocoons of lava.
There are still many features relating to rocky planets that must be simulated into Universe Sandbox, because current features are not enough. Progress so far has been great for developers, but I want to be able to simulate everything that can exist on terrestrial planets such as different weather systems and volcanic eruptions of magma, ice and smoke like black smokers.