It wasn't great, but it was alright. That twist in the middle had my head spinning a little, because I didn't see it coming at all... and the ending was pretty cool, but honestly... the rest of the book was pretty boring... 
 This was the first John Green novel I've read and I'm not impressed (a bit disappointed, in fact). :/ 
 I really like John as a vlogger and it was funny because, as I read the book, I could swear I could hear his voice sometimes. ;)