I Hunt Killers and Game to be gripping and gruesome thrillers. Barry Lyga found a way to top them in the finale, with many plot twists and satisfying character endings.
The first two novels involve Jazz dealing with followers of his serial killer father, Billy Dent. Blood of My Blood has Jazz going after his own family, who are far smarter and more devious than anyone could imagine, except Jazz. Billy's voice, which has haunted Jazz for his entire life, is now guiding him towards what he needs to do to make the world safe again.
I want it to be really clear that this is not a middle school novel. The descriptions are graphic and the the topics are inappropriate for young readers. Mature high schoolers and up will be racing through the novel, eager to find out what will happen. As the conclusion to the series, no character is safe, which makes it an even more exciting read.
This series is best read with no spoilers, so I will just recommend that you read the other two novels, then rush out for Blood of My Blood (it's not a standalone book). Lucky us, the wait is over.