I have been getting asked this question a lot.
"What is the age range for this book?"
I would put this book somewhere between PG and PG13. There is some swearing, and some romance but no lewdness. There is also violence of course as the characters struggle with themselves and their environment although the gore is pretty low. It IS a book set in a video game universe though, so there is a lot of death. Especially by the Main Character!