Echoing many voices from the other reviews, this book would probably look a lot different and have a lot fewer pages if it were to go through the hands of an industry editor. The typos from the Russian to English translation didn't bother me, but there was a fair amount of gumpf that could've been cut. At least half of the book must be dialogue, which was fine - I quite liked the stories that the many cast told - however, the same points were often repeated, with each next sentence elaborating further and further on the previous one, even though we got it after the first sentence.
It took a month to get through the first part of the book and get hooked, for Artyom to begin his travels, simply because of the information overload. It was a lot to take in, especially as I wasn't sure who the protagonist was at that point. The world was built up really well, but I have the feeling an editor would have cut or asked for the information to be spread around a little more.
The restrictions on moving from station to station also seems really heavy early on, desperately so, with people just flat-out dying between stations for supernatural reasons. If Artyom was so special, (one of the few who could actually traverse the tunnels) you'd think there'd just be a complete block on movement, or at least an escort service with someone who can go through them no problem. The tunnels in the latter part of the books just never seemed so terrible as those early ones.
The book's highlights are the world that has been built, the metro and its inhabitants at all the variously-styled stations. I tried to follow Artyom using the map in the front of the book, but sometimes got lost. Not all tunnels are on that map it seems. With each new station is an opportunity to philosophise on one particular political movement or other, or on spiritual or religious motives. It becomes apparent that the action is somewhat second to Artyom's journey, with lengthy passages exploring the role of God in all this, or fake Gods, or Man. Again, with a cut, these passages could have been made condensed and more concise.
From the comments, not everyone enjoyed the ending, but I was okay with it. Perhaps knowing that Metro 2034 exists was all it took. I do wonder what happened to Hunter though. Maybe the next book answers that.
A more condensed version would be a 5 star for sure. There were some great horror set pieces, especially on the surface with some eerie watching monsters. As it is: 4 stars.