As a description of an alien race designed for use in a role playing game, this book did a fine job of really building a culture that is sufficiently alien to be more than just a human in a rubber suit (or, this case, furry suit), but without making it so alien as to be unplayable. It was an enjoyable cover-to-cover read, and I it appears that it will also serve well as an easy-to-use in-game reference. Any longer and it would have been tedious; shorter, and it would have felt like it was missing something. The last few pages set up an adventure that was in itself an interesting read, perhaps superfluous to the core mission of the material, but I'm sure useful for Traveller referees looking for a nice framework in which to set an Aslan-centric adventure.
The really nice thing about this book is that it can be used, I think, by a Game Master playing any sci-fi style game, because the description of the Aslan and their culture is very rich, and the rule modifications needed to any other game system should be obvious and uncomplicated.
Hm. I'd go a step farther; I think the Aslan could make an interesting race in many fantasy settings as well. Have to think about that one.
The book could have earned a fifth star with more artwork as well as a single summary page of all the racial modifiers listed in one place. But I heartily recommend a place for it on the shelf of any fan of space opera, science fiction, or role playing games in general.