This is quite a serious question, I was asked to write few words about a similar game (not officially published yet) and I started to wonder what were the earlier programs of this type. This is partly engineering and partly physics problem. Many computer games use some kind of physics engines (like Havok), but that's not what I am looking for. I am thinking about computer games that are solely based just on physics - for example, my understanding is that Kerbal Space Program is actually "just" an interface to the underlying physics simulation (approximated, still quite accurate). Bridge Builder is another example of what I am thinking about (but I think I remember some similar much earlier simulation using FEM and running under DOS). I have a felling this kind of games was impossible on slower computers, but todays number crunchers can easily deal with dynamics of quite complex structures and systems, which makes this kind of games possible. However, I would like some examples to be sure my intuition is right (or wrong).