I really like the focus you've chosen, and thinking about megastructures in spaces and how they warp the area and other structures around them (until eventually they must fall). I really like the stage setting questions, and "Alternative Answer" in particular seems like a cool pbta-esque move to me.

This is a nice guided conversation for collaborative setting building, I could see it being used in a lot of contexts.

I'd play this. It's high-improv in the character side of things, but the nod to Microscope helps with that and I think the questions will offer footholds to the Conversation. (I'd hoped to play before commenting but didn't manage, sorry.)

I'm interested in not giving an actual size for the star map; the distances between the scraps would influence the narrative. A tiny map would force jostling, a big one would allow the structures to be entirely autonomous but allow for conflict at the edges of their spheres of influence, and I think I've just persuaded myself that you're right while typing this!

Your rules and the way you laid out and present your game is very clear and easy to follow. Reading it, I felt it would be easy to play and the questions you have as prompts were thematically appropriate and interesting! The only thing I foresee having problems with is doing the first person rp stuff without having a better idea about my character and their motivations etc. but I think people more used to improv wouldn't see this as problematic. All in all, I think it's a cool little game with a nice theme, kudos!

I was a little confused about what the X-Card was, but it lead me to reading about it on google, and I discovered a nice little tool for games! 

Formatting for this game looks beautiful! It really is pleasing to the eye! I also am a big fan of the idea of developing a "space" map with mega-structures and creating a world for them!

I definitely could see this being a great way to create a world for another game to play within such as D&D!