Card (and his collaborator Aaron Johnston) knows how to write a good read, but it seems like he can't do much more than that. The characters not only felt flat, but they also felt too familiar, like Card only writes certain kinds of characters and writes them over and over. From that perspective, perhaps the most intriguing character was Lem Jukes, who serves as a bad guy (of sorts--the aliens are the real bad guys). We got at least a glimpse of who Lem is and what motivates him, and he was intriguing because he's neither the too-thoroughly-good character that Card seems to love so well for his protagonists, nor is he all bad. He acts with callous disregard for other people, he has petty motives of trying to outdo (or is it please?) his father, yet he's not a paper-thin bad guy--he has regrets, he has altruistic motives that bubble to the surface, though even his altruism is intertwined with self-interest and egotism. 
 Bottom line: it's nothing special, but it was a decent way to pass the time.