Let me start off by saying I really enjoyed reading this book. Altered is full of action from the get-go and the four boys, Cas, Trev, Nick, and Sam, are well-written and intriguing characters. I really want to know more about them and their backgrounds.
If I had to rate this book based upon how much I enjoyed it, the rating would definitely be higher. However, there were a few issues with the story that simply cannot be ignored.
Issue # 1: Anna
She isn't an unlikeable character, but she's not very interesting either. As I was reading, I kept thinking the story would be a lot stronger if it had been told from Sam or Nick's perspective. There's also a twist pertaining to Anna and Sam's past that I didn't care for, but it's something that probably won't bother most people. The twist doesn't ruin the story. I was just slightly disappointed by it.
Issue # 2: The Branch
Only a minimal amount of information is provided about this organization. We don't know why it exists or why the boys are being subjected to experiments. It's clear that Anna's father, who works for The Branch, suffers from a guilty conscience. However, the other agents and scientists involved in the alteration project are one-dimensional and they are essentially evil for the sake of being evil. These characters have a "We're going to make a lot of money and take over the world" mentality. They're cold, calculating, and lack humanity. It would have been great if the characters connected to this organization were a tad bit more complex.
All in all, this is a great debut novel. I'm intrigued by the story and cannot wait to see where the author will take this series.