From publisher blurb:
Assimilant Menace! is the first in a new line of supplements for the White Star roleplaying game from Barrel Rider Games. It expands upon the Assimilants, a race of bad guys found in the White Star core rulebook. The book is compatible not only with White Star, but all d20-based OSR games with a foundation on the world's most popular RPG.
Inside are several new variants on the basic model, new cybernetic implants for the Assimilants or your characters to wear, including fearsome new Rigs. Now you can send three new threatening starships against your players, including two variant fighters and a cruiser.
Not everyone's bad, and this book presents two new classes for PCs that have been liberated from the Swarm. The Free Servitor gains cybernetic enhancements and can help coordinate his allies. The Free Node Brain links symbiotically o a starship to greatly enhance its capabilities.
This book draws inspiration from its source material, and also presents ways to use the Assimilants as more than mindless cyberzombies, but also as stealthy infilitrators and other threats.
Keep on the lookouts for further books in the Menace! series, each of which is going to highlight a new enemy for your group.