Well, I would say most of the basic functionality is working as of Feb 13, 2022. One big issue I am having is that the program exits with a code 3. Obviously, something is wrong, but so far, my searches have not revealed anything that helps me find out what it is. So for now, well, there are more important things to do.
Eventually I want to dispolay the Energy of the objects, as well as things like Potential Engergy, which, it seems, is difficult to do if you have 2 or more moving bodies. Also, things like angulare momentum, stuff like that. Sort of like being back in Physics 21.