Warcross by Marie Lu
My rating: 4 of 5 stars
Reminds me of last year's Arena with a younger cast and more of a mystery. The questions about who can and who cannot be trusted and what motivates the various players and hackers are well presented; the worldbuilding, on the other hand, is weaker than is usual in a Lu book (hence the four, not five, stars). At times it felt like Warcross was something like Capture the Flag in a virtual environment, but then there were other elements that weren't completely explained but hurried through. On the other hand, the worldwide fascination with the game and the obsession with gathering points and "leveling up" feels very real in a world where getting "likes" and "follows" is important. How the series progresses will be interesting.