Despite it being clearly aimed at the young adult market, I enjoyed this book and read to the end within a couple of days. There was quite a lot of aggression, fighting and violence but also some teamwork and mutual cooperation going on. Of the 12 'bloodlines' featured in the Endgame, we followed quite a few and I did find it problematic remembering who they all were. I also became a bit confused over the timespans - some bloodlines were supposed to have been around for 9,000 years whilst others were much newer, so did the aliens visit at several different times during human cultural development? There were hints of other bloodlines having died out.

I enjoyed the book and would read further instalments in the series, partly because I can't yet see the 'big picture' and would like to know what's going on from the aliens' point of view, and what their motivation turns out to be. I suspect that the whole 'fight to the death or else' objective is misleading (for the players) and they'll have to cooperate to save humanity.

I understand that the film rights have been bought and in truth this would make a blockbuster of a film. It would have glamorous, athletic stars, amazing locations, plenty of action and a plot that moves along at a spiffing pace.

The writing quality was more than acceptable but there were some formatting errors in my (kindle) version - hopefully these were sorted out.