Has anyone looked at this early release yet? http://store.steampowered.com/app/402710/
Single player, MP, and MP coop available on your own server. Very early yet, some impartial game play video below, "this game is buggy as hell", but looks like it has good potential. No, not procedurally generated worlds, each planet is crafted for detail and to be experienced. These videos are after the most recent patch BTW...