I briefly searched, but did not see mention of this Awesome sandbox game! Seems like it would be right up ED players alley since it quite accurately tries to portray many configurable planetary and system aspects and physics.. I'm having lots of fun messing around. Spawning Sagittarius A in our solar system was the first thing I did and unfortunately, we're all dead, sorry. But yeah, you can create or destroy in a graphically impressive engine for sure. Now on to terraform mars.. Lots of YT vids. You get a steam key when you by the game from the dev. Many videos at the link below or just search YT for tons of example of what can be done. I've been lost for a few hours in this game before realizing it.
http://universesandbox.com/2/
http://universesandbox.com/2/