Unmarked spoilers ahead!
Tropes found in the novel:
- Bittersweet Ending: Following their discovery, Homo Ludens leave Earth en-masse.
- Brown Note: Little Pesha incident has village population encounter artificial lifeforms that are this to most humans, keyword being "most".
- Character Narrator: The book is explicitly stated to be written by an in-universe character, with Fictional Document qualities being a deliberate stylistic choice of his.
- Fictional Document: About half of the book consists of multiple Fictional Documents.
- Hidden in Plain Sight: Homo Ludens run a facility that sorts humans to find candidates for uplifting and assimilation into their ranks. They disguise it as so-called Institute of Eccentrics that supposedly sorts humans to find "metapsychically talented".
- Intelligence = Isolation: True for the Homo Ludens, at least in regards to the rest of humanity.
LOGOVENKO: That varies. It's not as simple as you think. The most typical model of the Ludens' attitude toward man is the attitude of an experienced and very busy adult for a cute but terminally annoying kid. Then picture the relationship: Luden and his father, Luden and his best friend, Luden and his teacher...
- Properly Paranoid: What COMCON-2 service perceives as their mission.
"We are workers of COMCON-2. We are allowed to be called ignoramuses, mystics, and superstitious fools. There is one thing we are not allowed: to underestimate danger."
- Screw This, I'm Outta Here!: The Wizard of Saraksh pulls this off within first day of visiting Earth - presumably due to sensing Wanderers.
- Secret Test of Character: A global scale Secret Test of Character, no less.
- Serial Escalation: One of the Luden admit that human psyche hides other inactive systems, similar to the one that allows creation of Homo Ludens, and not even them know what would result from their activation.
- Tomato in the Mirror: Toivo Glumov.
- Took a Level in Cynic: Mak Sim, idealistic protagonist of "Inhabited Island", is working for what is effectively a world-wide secret service. His worldview changes accordingly, both between the events of two books, and between the events this book describes and supposed present day.
- Transhuman Aliens / Human Subspecies : The "Homo Ludens".
- Transhuman Treachery: Played with. Homo Ludens are not threatening humanity, since every candidate is screened in regard to their morals before the initiation, and rigorous teaching process ensures they stay that way. However, they have a hard time maintaining their human circle of friends and family. See Intelligence = Isolation entry above.
- We Will Have Perfect Health in the Future: A norm for the Noon universe. In fact, here what draws attention is an inexplicable series of refusals by new mothers to let their kids undergo fukamization procedure.