Trying to describe Starcruiser Anonymous in a few short sentences is a daunting task. I've tried several times, and I still haven't come up with a summary I really like. The very nature of the series makes summarization difficult: any single plot thread you pull from the story represents at best a third of the entire thing.
In a sense, Starcruiser Anonymous is three interlinked stories:
Admittedly, the Aroruan plot thread is subordinate to the others, but it does account for a large portion of the action.
Meanwhile, there are other, smaller stories being told, including:
Amazingly enough, it all fits together into one reasonably coherent tale.
(Notice that rebellion seems to show up again and again? I didn't plan that; it just sort of happened. I'm not sure what, if anything, it means.)
Starcruiser Anonymous involves a dizzying array of characters, most of whom can be assigned to one side or another. The two big sides are the Zakavian Empire and the starship Anonymous, both of which are described in more detail in the prologue.
The Anonymous, a giant starship of apparently alien design, was launched by a group of northern New Jersey towns who sought to flee the devastation on Earth in the late 1980s and after. Its passengers and crew have mostly been content to be left in peace, but you know that's not going to last.
The Zakavian Empire is the union of two spacefaring peoples, engineered by its current ruler, Emperor Vakaz, who had come to rule boht through a series of odd circumstances. Aside from Vakaz and his cronies, no one is very pleased with this situation, hence the Empire's rather shaky grasp on stability.
Although Starcruiser Anonymous is set in the Sfstory universe, you don't need to know much about Sfstory to understand it. Little of the long, convoluted history is referenced, beyond some background details that help establish the setting. I've made up a list of some of the Sfstory references that might provide some insight. Or they might not. You never know, do you?