About halfway through I came to look at the reviews and saw a lot of DNF results.
I was already committed at that point… but definitely shifted to speed-reading and skimming.

This hooked me early on, a heavy read with dense language and a patient narrative, a story where I could see hints of the Dark Tower comparison, but as it wore on, I found the reading didn't get any easier, the characters didn't get any more likable, and the story didn't move anywhere I was interested in.

It was a very cool concept with some fabulous scenes of the wondrous and bizarre, especially with the creepy flight through the bug-infested abandoned subway station, but completely overwhelmed by scenes of wallowing and self-pity that became so deep that the eventual reveal of the 'loss' behind it all can't help but fall flat.

This was good but... heavy.
That's not quite the right wording, but it's close.
I've read a few "people reunite to finish what began X# of years ago" books and this has some of the more dense ideas among any of them.
I understand the ending mostly, but not completely. And I think I understand the majority of the symbiology in the novel.
I somehow forget every time that every Max Gladstone book is the most complex book I've read since I last read a Max Gladstone book.
Very good book, but much more thought provoking than your standard "reteam to fight what we fought against when we were younger" type books.

Max Gladstone uses the fantasy quest plot to tackle the mythology of redemptive violence, U.S. post-9/11 and surveillance society, the teaching of history, what useful activism looks like and what the challenges of it are, and class and gender relations, all while interrogating the conventions of bildungromans and fantasy quests.

I'm still mulling over whether I think he entirely succeeded, but points for ambition.

Just over ten years ago, five college friends discovered something extraordinary. They called it “spin.” A mathematically derived force that allowed them to hitch rides to alternate earths and perform magic-like feats of improbability. For two years they had adventures in these “alts.” They got to see dinosaurs. They saved the day in villages across hundreds of worlds. They even met princesses and royalty. Then they failed, a friend died, and the fellowship broke up. Ten years later, Zelda needs to get the band back together to save the world.
Max Gladstone’s “The Last Exit” has a premise that I deeply love. The heroes are not wet behind the ears kids on their first journey into the big wide world. No, they are scarred thirty-somethings. Tired and broken by failures and heartache. Their adventuring days are in the past. Now they just want to live their lives as doctors, tech millionaires, and mechanics. They’re heroes that are burned out but know they need to do something to fix their mistakes.
Gladstone’s characters are a delight. They’re not witty or charming like main characters in fantasy novels tend to be. Instead, they’re realistic while still being likable. Even though their interpersonal drama is toxic you can see how they were once best of friends and a friendship that strong doesn’t just end, even after a ten-year gap. You find yourself rooting for them, and praying that at the end of it all they can just get some therapy.
I don’t want to spoil anything in this, because honestly, it is a story that needs to be read. No description could ever convey what actually happens here. What I do want to say is that this book is the perfect millennial book. Yes, it sounds corny, but this book captures the feeling of the millennial generation. Not the “everything is awesome and memes” feeling. No, this is “when we were teens we watched 9/11 happen live on television at school and everything got worse since” type of millennial.
The story goes out of its way to play into that generational trauma. These broken adults were once idealistic teens. They were promised what we all were, a glowing future, a better world. The internet was bringing everyone together and soon world peace would be within our grasp. The economy was going up and that massive college debt you were taking one would be nothing compared to the salaried career your degree assured you. Captain Planet was cautioning the dangers of pollution, but we Planeteers could stop global warming by turning off the sink when brushing our teeth!
Then we entered into a forever war. The economy had a once-in-a-lifetime collapse, twice. All the internet has allowed us to do is be jerks to people across the planet. Deregulation and industry seem to ensure that the next generation won’t have ice caps. The characters here embody that feeling. The feeling of stress, betrayal, failure, and fear. Their journey through the alts is less about saving the world than just being able to do something that makes a difference. It’s heartbreaking and struck a chord in my cynical heart. Especially when they bring a teenager along with them who still believes that the future can be better.
For that, I love this story. Yet at times it also made it hard to read. Yes, there’s hope here, but it is distant and hard-won.
The prose at times is dense, jumping back and forth from the present to the past, and relying heavily on metaphor. While at times it caused me to have to pause and reconsider what I just read, it is beautiful. It enhanced that sense of loss and nostalgia that the characters are going through.
I recommend this book to anyone who feels a little hopeless about the world right now. Who feel that things should have been better. Read this, feel your feelings, and take hope.