Downloaded KSP Demo https://kerbalspaceprogram.com/
This game is quite fun. It’s got Newtonian physics, atmospheres, and other fun space-travel related thingies.
Its basically a sandbox for rocket building, and space travel. You piece together rocket (fuel tanks and engines), try to fly into space, get into orbit, land on Mun, etc..
Here’s high-lights of my maiden flight to the Mun.
one way trip :( (RIP Jeb)