I really love the first 2-3 hours of gameplay, but once your base is established there isn't much left to do.
I'm sure the developers are kicking around ideas for the beta/launch, but something small in the meantime would be great to keep engagement.
A few suggestions:
Make an overall quest to escape the solar system.
Example: Need to recover a special rocket engine from a mountain top on Terran using a winch, which forces you to build a drive able pathway to the peak
Example: Need to mine Helium-3 from super deep caves on the moon.