the SE devs themselves also said making a planet is impossible and not performance friendly, but they did it, although it means it is now only restricted to 64bit systems :P, and still have some performance issues, but I can say that it is quite impressive for such a feat.
Now they need to work on the survival aspect a lot more, already sent some suggestions about it, for example multiple "sectors" like avorion, optional end game boss fight, quests that you can pick up from stations that you can find, neutral/friendly npcs, but obvoiusly they all need plenty of time.