The most long-lived series of Traveller fiction is that of Jefferson P. Swycaffer, who envisioned a Traveller universe, but one not set in Charted Space.
This seventeenth review covers the sixth of the Concordat books, and the second one published by New Infinities Productions (best known as the publisher of Cyborg Commando and the later Gord the Rogue books).
About the Story
Voyage of the Planetslayer continues the story of Traviella-i-Tel and the crew of the Coinroader, but this time they're in a new adventure--enlisted by the Concordat to crew the Planetslayer, whose mandate is to terraform the planet Kythe-Correy. Sadly, that terraforming must begin with the utter destruction of the (non-sentient) life currently extant on the planet.
1. Not in Our Stars
2. Become the Hunted
3. The Universal Prey
4. The Praesidium of Archive
5. The Empire's Legacy
6. Voyage of the Planetslayer
7. Revolt and Rebirth
The "A" plot concerns the Planetslayer's trip out to Kythe-Correy, the moral dilemmas surrounding whether the planet should actually be destroyed, and ultimately some conflict over that. The "B" plot centers around Stasileus, the slavish alien introduced in the previous book, who is now trying to understand what makes humans work--and what they really want. The "C" plot takes place back on a nearby world, where a court case is trying to judge the legality of destroying a planet (a bit too late, it would appear at first). All of these plots neatly (perhaps too neatly) dovetail together by the end of the book. The "D" plot is a largely offscreen romance between one of the crew members and one of the scientists who is overseeing the planetary destruction.
Put that all together and you have a book-length plot--though in my opinion, a pretty thin one.
Genre & Style
Like its immediate predecessor, Voyage of the Planetslayer is gaming fiction. As I said in my previous review, I think Swycaffer's writing is much better suited to this subgenre than to the more literary work that he was trying to do for Avon, and as a result I enjoyed this book more than any of their earlier Avon books (despite that aforementioned thin plot).
The biggest problem with Voyage of the Planetslayer is that it takes forever to get going--and that's somewhat understandable, because by the time it does get going, there are only a couple of major events that occur before the book heads quickly toward its conclusion. I also found the plot threads a little too scattered at first. Not knowing that they were coming together, it felt like the book was really being padded out (though I was relatively happy when they did come together, other than the fact that I thought that Stasileus' understanding of human nature came much too fast).
When I wrote about The Empire's Legacy, I said that I found it largely revelatory for how much it detailed about Swycaffer's Concordat Traveller setting. This one is nowhere near as deep, but it does successfully build upon the setting elements from the previous book--particularly the Empire, its genetic engineering, and Stasileus' race--such that I felt like I'd seen yet more hints of a rich setting.
Overall Voyage of the Planetslayer was every bit as enjoyable of a read as its predecessor, it was just over a bit too quick with not a lot happening. I've thus given it a Style of "4" and a Substance of "3".
Applicability to Mongoose Traveller
Voyage of the Planetslayer seems like it was probably an adventure that Jefferson Swycaffer ran for his players. It's got a bit of moral dilemma and a cute little mystery that together could form the basis of a couple of hours of play. Though some plot elements are drawn directly from Swycaffer's unique Concordat universe, I think you could pretty easily adapt the story for use in a Third Imperium Traveller game. I'd even suggest doing so, as I think it's likely to be a unique adventure, quite different from what you might otherwise run.
Conclusion
Voyage of the Planetslayer is another successful (though not outstanding) novel from Swycaffer & New Infinities. It's fun to read, and though the actual plot is pretty shallow, it could still make for a couple of hours of enjoyable Traveller play. So, go read it and consider adapting the plot into your own Traveller game.

