Abandoned? What was unfinished? I was satisfied when I played it. My only complaint was something about population growth or the ageing of people being too quick IIRC.
Have you tried the Colonial Charter mod? Adds an insane level of content.
Also, there are now dozens of games that took the concept and ran with it. From Space Base to Manor Lords to Timberborn.
No I haven't, sadly I can't find the real one on Steam as it suffers the same problem every other Steam game does; hundreds of suspicious copy pastes of original mods.