Up for Architectural Review?

Well, okay, feel free to comment on my Ruby. There's room for improvement.

I have been playing at some code for a while and decided to make it
actually "work" today. That means prioritizing a very few processes
and pushing back on scope creep. It is at the limit of my complexity
competence so there are lots of issues, fragile places, and room for
improvement.I've been doing a lot of reading and am now trying to get
my coding skills up.

https://github.com/makhidkarun/Star_Merchant

I would appreciate feedback on how to make it better in the sense of
Ruby, architecture, and fun.

Thanks!

Leam