Where to begin... I picked this up expecting a quirky, humorous, adventure of a science-fiction novel. 
 Needless to say I was wrong. Not completely, of course. This book is definitely quirky, and there's some sly humor muddled in-betwixt the more blatant jokes. Still, a fitting alternate title for this book could very well be "The Science (-Fiction) of Regret". 
 Now, that's not a bad thing. So long as the reader is willing to suspend prior expectations and live within the narrative structure Yu provides, it's rather good (if a little off the wall). 
 Eccentric and meditative. 
 So, things I liked: 
 So much meta. The entire setting of the book pokes fun at science-fiction and science-fiction concepts and I love it to pieces. 
 Humor. Specifically, see above. 
 Prose. Deeply reflective. A little wordy, but it maintains internal consistency, and it flows very easily. 
 Things I had more trouble with: 
 Some of the narrative events were quite odd... the plot struggled a bit in the middle. It still worked, but it was definitely on the edge of not working. 
 I suspect that (like most works of literature) this needs to be read a couple times to really let it sink in.