Like many 4X games I've played, Star Ruler has managed to suck me in, though it was kind of a rough start. My AI opponents were very aggressive, declaring war against me with no provocation and while I was still struggling to figure out the tech tree. Luckily, Star Ruler has a feature no other strategy game would bother with - you can turn off all of the AI competition and play in an empty galaxy.
The first time I did this, I was swarmed by pirates within minutes and thoroughly wiped out. The next few times I did it, I was able to meet the pirates with a fleet that wasn't quite large enough. They just kept on coming, more than I could handle.
So I turned pirates off too.
It was an interesting way to explore the tech tree. I never really got a good benchmark for ship power, but I did get to see a few cool civilian things. There is something awe-inspiring about having a hundred well-developed worlds, going into your systems-control screen, ordering them all to build exactly one colony ship, and then seeing a massive swarm spread out into the galaxy. Then setting the speed up to 10x, waiting a couple of minutes, and then doing it all again. Spreading out with geometric growth is just an incredible experience. I highly recommend it.
Alas, I have not yet built a ringworld however. I've started one, but the resource requirements are an three orders of magnitude higher than what my planets can churn out. I expect that it requires mastery of the use of haulers and other resource-shifting tricks. I need to figure out some way to concentrate a galaxy's worth of resources into a single system.
It's a learning process, and one I enjoy despite the fact that I'm basically just playing solitaire. There's a lot about this game I still don't understand and the opportunity to explore without the pressure to win is one I value.
I think I'll start another solo game in a smaller galaxy and see if I can build at least one ringworld (and perhaps some other high-end ships) and maybe get a handle on the game's more powerful tech combos. Who knows, I might get through the whole 20 hours without ever going up against an actual opponent.