As brevity is the major attribute of this story (being only 88 pages in length) it probably isn't a huge compliment, or a definitive indication of the quality to say that I easily finished it in one sitting. But I have to say that I did generally find `The Six Directions of Space' to be an involving, taut and extremely well-paced novella. It's been a while since I read a science-fiction story this short and this enticing, aided in no small part by a flowing prose that made reading virtually effortless.
But the reading isn't always so smooth. At times Reynolds' descriptions become quite dense. The problem for me was the occasional structure of sentences with words that I didn't find particularly expressive of what was being described, or conducive to picturing in my mind the technological structures in the Mongol Expansion and beyond. Also, when Reynolds isn't detailing complex technologies, the dialogue that intersperses it is surprisingly colloquial with common English phrases throughout (*this being used by a people derived from Mongols in some distant future). Personally, I would have preferred for the characters' language to reflect more of their intelligence, or at least to have had some ethnic aspect that denoted their Mongol ancestry in their dialect. But these only prove to be minor stumbling blocks, because before you're aware Reynolds has moved on and the story becomes a real page-turner.
It's an underrated quality, but commendable nonetheless I find when an author is able to coin names for people and places that ring true in the readers' mind. So often in science-fiction and fantasy, extravagant and unpronounceable names mar excellent storytelling. However, while I was impressed by character names that rolled off the tongue and Reynolds world-building in general, I would have welcomed some more background info. (on the heroine Ariunaa, A.K.A. Yellow Dog in particular), or even a short paragraph detailing her appearance. I think that would have endeared me to her more. Or maybe it's enough just to know she's a ruthless lesbian spy. I'm not sure. But that isn't to say the characters don't make a vivid impression on the readers' mind, because they do, especially for such a modest page-count. Perhaps what feels lacking is a depth to these characters that a novella-length story is unable to provide.
`The Six Directions of Space' is a little gem despite its imperfections with a story that clearly has bags of potential, and one which I hope Reynolds will develop into something more substantial in the future that I will definitely be keeping an eye out for.