To answer your questions, I don't work directly on this game prototype anymore. I ran into design issues with AI and subsequently got distracted by another project.
However I am still working with this particular space engine today and the game in question is going good, if a bit slow. Interestingly I still retain ALL the functionality from this particular prototype, as I intend the system to cover large scale conflicts that occur in the game.
The art was always a roadblock for me as a programmer, but I have actually drawn the assets myself now. I don't think I will be publicizing the said newer title until it is due for release (which could be a long time looking at my track record).
At the time, perhaps it would have been successful; although I also thought at the time Starsector would actually come out in a reasonable amount of time and I would just be squashed by them commercially as I could never compete artistically or financially. While I think the game could have been fairly successful, it would have always been a really niche project - I was never happy with how the gameplay systems were coming together and it just never really became fun to play, it always needed more gameplay systems. I was also never particularly good at ship design so that basically doomed it going commercial.
As for the source, I don't know about releasing it for this prototype as it would require some pretty solid effort on my part to re-separate it from my current project - you definitely don't want to be tracking down the issues I have had with the original 2012 engine!
(Bonus) An interesting side project for homeworld developed from this particular prototype: