This book is masterfully crafted in my opinion. And it made me cry. I don't even know how to structure this review. 

Maybe I start with Sadie, Sam and Marx (!) since we follow their rather complicated friendship through several years. All of them are written amazingly well in my opinion, the way they develop over time just makes so much sense and makes them feel so real that you could swear you recently watched them talk about one of their games on a panel at a convention or something. Sadie and Sam are people that aren't easy to get along with and watching them form this friendship was heartwarming, while also being a little heartwrenching, because the book makes it clear quite early on that it won't all be sunshine and rainbows. I have complicated feelings about both of them, I liked them a lot while disliking them to a certrain degree if that makes sense. The things that frustrated me were very in-character for them. Sometimes you saw so clearly where their communication went wrong  while having to watch them act how you knew they would anyway. Argh. Meanwhile, Marx is just so extreamly easy to love it's incredible. He is kind and smart and empathetic and understands people so well.. idk, if you're able to finish this book without loving him please let me know, I want to know if it's possible to dislike that man. 

I also loved the focus on video games. One can tell that Gabrielle Zevin loves games herself and put a lot of research into representing this aspect of this book well. The love for video games, their infinite possibilities and infinite tomorrows is everywhere: how Sam, Sadie and Marx talk about them, how they are used to explore themes, how much effort was put into taking you on a journey to develop a game (I really want to play some of these completly fictional games), how they form a connection between characters. Everything in this book is a love letter to video games and I think especially people who love them as well will greatly enjoy this aspect of the book (like myself). I don't think you have to be a fan of video games to enjoy this book though.

A few short things: I liked how this book did a good job (in my opinion) to show problematic things without making them seem okay. As well as the way a situation is always cleary framed by who is experiencing it. Gabrielle Zevin also does this thing where she reveals important details or includes a little interview snippet from the future at just the right time to be impactful. 
Last but not least: This is one of those books where you will at some point go "Oooohh!" because the title and the cover suddenly make so much sense. I loved it, they were chosen perfectly.

While I absolutely loved this book, as one can tell by this review, I do think that one should critically reflect the disability rep. I'm not disabled so I am going off of other peoples voices here, who talked about how Sams disability was treated as something to overcome instead of being a part of his identity. He resents his foot and the difficulties it brings a lot and I feel like especially for non-disabled people, stories about disability often become either "inspiration porn" or a story about a sad person who hates this part of themselves. These tropes can play into harmful stereotypes, which is why I think it's important to keep that in mind and check ones own assumptions concerning disabled people.