This is a narrative exploration game driven by a deck of cards. You play a group of explorers traipsing through a forbidden place, and each draw from the deck presents you with obstacles or questions.
The gameplay is tense and atmospheric, and the book's layout does a great job of echoing that mood. Unusually for a narrative game like this, you *can* lose characters, and it's fully possible for you to lose the game. Whether or not this happens is up to chance.
For me personally, reading Chiron's was a little weird, since it's mechanically and thematically almost identical to a thing I published a month ago, and Chiron's has been out for almost a year. I honestly didn't know about Chiron's until right this hour, and I was designing in reaction to Bleak Spirit and Sleepaway and Annihilation, but I wish I'd read Chiron's earlier---both because it's a great game, and so I could have steered harder in a different direction.
Overall, if you like stories about the unknown, about horror and struggle, about discovery, and about the deep weird of places that should not be, definitely check Chiron's out.
It's tense and fun and easy to read, and worth adding to your library both as a one-shot and as a solo/writing prompt.