I would definitely say that 2033 is my favourite book of the three. That said Glukhovsky has gone on record saying that 2033 is an adventure book most liked by teenagers, which I was when I read it the first time more than a decade ago. Exploring a new, yet familiar world, closely resembling Wasteland and Fallout, was amazing and I've finished the book in a binge in about two days.
2034 was enjoyable, but it felt like an expanded universe book with characters largely disconnected from the original story. I enjoyed exploring the parts of the world that we haven't seen before and the epidemic plotline was neat. It didn't captivate me like the original did however.
I've only read 2035 very recently, and I can say it is the least favourite of the three. My main gripes with it is a radical change of writing style, lack of mutants and shoehorning political opinions into the story. The original book thrived on being detatched from reality with political groups being rooted in the late 1990s Moscow political climate. Why 2035 would suddenly retcon this and switch to criticizing real world modern politics is beyond me. It was really off-putting.
Agreed totally about Metro 2033 and Metro 2034. And while I see and somewhat agree with your points about Metro 2035, I have to say it might be my favourite novel of the three (I'm kind of undecided between 2033 and 2035, but I voted for the latter to make things more interesting and I kinda anticipated that the former would be most popular).
I am totally with you on removing mutants from the story - it's weird, uncalled for, and serves no purpose. Glukhovsky could have gone on his political crusade without making a large part of his own universe completely disappear for Moscow. The post-nuclear ecosystem has always been a large part of the franchise's charm, and it has remained so in most novels of the Universe of Metro 2033 series. As for the writing style, apart from the lesser focus on atmosphere and setting the scene, I think I preferred it. It's more raw, brutal, and speech works more naturally; the punctuation is chaotic and irregular, just as it actually is when people speak in reality.
Regarding the political critique: when you think about it, Glukhovsky was still quite young when he finished the first draft of Metro 2033 - in 2002, when the first online version appeared, he was like 23 - but according to various sources he conceived the idea for the book when he was just 15 years old, inspired by his gaming habits in Fallout with the added flavour of the Moscow setting. When the first book came out online, its reality was still quite relevant for the 1990s.
Move forward to Metro 2035 being published in 2015 though and the author is now 36, an experienced journalist and a writer with many more published works to his name - he has travelled the world, speaks numerous languages, and came across his own issues with the Russian government. The book reflects his life experiences and changes in views, and the new political critique is much more relevant to present day affairs. I personally liked it a lot, but this combined with the other radical changes in style are likely to make Metro 2035 a love it or hate it kind of novel for fans.
Thanks for sharing your views on this Komo, interesting to have a discussion going about this! Hopefully more people will pitch in too.