I'm new to the Alternity game line, so maybe that's jaded my taste for this product a bit. This book seems to approach the game from a much 'harder' science viewpoint than I cared for. While there is a broad overview of the Aegis system, much of the info about individual planets is pointless mathematical detail that I couldn't have cared less about. It felt like I was reading a college textbook. Instead of fun, interesting descriptions of the planets that I could use for crafting adventures, a lot of space is spent telling me about axial tilts and planetoid density. Snoozarific. Players don't care about that junk. They want to know about cool places to visit, daring adventures to be had, nifty lost civilizations to explore. Not what degree of arc some clouds cover on a planet's horizon. Unfortunately, this book has very little of the former, and a lot of the latter. If that's what you're looking for, then, hey, this is for you.
Granted, there is a lot of info about the waterworld "Bluefall" crammed into the book. It's just that much of it is boring, and I found my eyes glazing over, and that I was skimming large portions of each chapter trying to find something interesting about the other planets and people being described. Even though there's a rather lengthy adventure scenario included, it too was not very exciting.
I suppose if you plan to base your campaign out of the planet Bluefall, then you can certainly find use for the NPCs and the map of popular islands and the history chapter, but unless you're a die-hard Aegis system fan for some reason, I'd say give this product a pass. Aside from some descriptions of scuba gear and water craft, which are just about necessities on the water planet that the book focuses on, there isn't enough generic material to even try exporting it into another more generic system of your own. Perhaps the information of the system's culture and government could be a useful example for designing your own system, but at the very least I'd suggest picking up the cheapest copy of this book you can find, because there's not enough to it to make it worth your while otherwise.