The Giver is remarkable for well how it builds a dystopian world by not describing things. Jonas is an unreliable narrator in the manner of someone who has been gaslit, he doesn't know what he doesn't know. I'm very glad to know this has sequels.

I'm keeping my descriptions minimal because talking much at all about so short of a book would spoil major portions of it. Suffice it to say, I liked it, I'm ready to read the rest of the quartet, and it's a dystopia such that the most chilling parts of it lie in the implications of what is missing from Jonas's understanding. It doesn't rely on mystery, exactly, just that as Jonas gains some understanding of what was absent from his life, it implies even more things that he hasn't yet learned were missing.