PULSAR: Lost Colony Forums

http://store.steampowered.com/app/237870/

something along these lines for planets maybe
not quite so sandbox open build i guess.
although some sort of resource / space engineer survival mode thing could be used

I have actually bought that but I'm still to get around to installing it D:

I've played it a little bit. It's a pretty decent game and the crafting system allows for some pretty cool and unique creations.