Being a companion novel/ sequel to Starflight, I’m not sure how much to say about it.
In Starflight the perspective is Solara and Doran (mostly Solara if I remember right). And the adventures she has running from her home planet.
Starfall follows Cassia and Kane. The misadventures that happen with them and how it turns out.
I was pretty intrigued the last half or so of the audiobook. And the last 20% was intense!
It does deal with some addiction. If you are sensitive to that this might not be for you.
And overall I think the duology is a 3.75/5 stars.