Limitless Horizons is a fun, light read that sparks a lot of ideas, but doesn't always develop them in full.
The product starts with a broad definition of pulp sci-fi, which helps define what this book plans to do and not do. While i do not agree 100% with the authors definition, it's a usable definition that helped me figure out what he was trying to achieve.
The rest of the book consists of 17 pages of rules (Racial Aspects, Scaling, Ship-to-Ship combat, Gravity, etc), a 10 page sample campaign background, and a 10 page adventure.
I was very satisfied with this book, especially for the price. The ship-to-ship combat rules are useful, the ideas on ships-as-player-characters spark some great ideas, and overall the book is a nice source of ideas and "small quick" rules additions.
I would have liked to see maybe a few more pulp sci-fi PCs given as examples, as well as maybe a few quarter-page campaign snap shots showing different types of pulp sci-fi campaigns (ie the Space Cop campaign, the Space Pirates campaign, the Planetary Romance campaign, etc)