I don't write a lot of reviews, but this book warrants one, as it needs to have more love. I was concerned that Aethera would be overshadowed by Starfinder, but this game is completely different. Rather than being the traditional D&D-in-Space sort of gameplay, this campaign setting has a feel that is singularly unique.
Within Aethera, there are a significant amount of campaign points that could be used as story arcs. The writing is top-notch, and it's easy to find some bits and bobs that you could potentially use in a campaign. It's even easy enough to use fairly toss-away ideas as the bases for whole campaigns.
Between the dieselpunk-style technological development with the political structure that addresses colonialism, imperialism, and authoritarianism vs. individualism, it's easy to create just about any sort of campaign that you want. Each planet in the Aethera system, and each location and story arc allows for a different type of science fiction - which I feel is probably the most interesting aspect of this campaign setting. If you want to play a game that's built around political intrigue set in a sci-fi post-war environment, you could easily do that; likewise if you wanted to play a Fallout-like post-apocalyptic style game, that's available as well -- just head on down to the human homeworld of Akasaat -- and likewise, the human homeworld has hive-like arcologies of people that exist on top of each other with glitzy, powerful entities living at the top of the heap.
There's something for everyone in this book. I highly, highly suggest it.