You could probably make a poptarts are sandwiches alignment style thing out of this.
Basically, any video game with an explicit goal, or set of goals is just a puzzle game with extra steps.
What buttons do you push, when do you push them, what does this accomplish, how does that lead you to your end goal, etc.
You could even argue that multiplayer tactics constitute a puzzle, a more social puzzle.
Yes, this is reductive, but this is a dumb showerthoughts post.
You managed to understand Stellaris?
I got far enough to figure out that the game takes forever because of the 10 year peace treaty period (which they added for balance).
I used to understand Stellaris before they added so, so many things to it. It’s practically a different game now than when I first bought it and I have literally none of the DLC lol