Several of the stories fell flat for me. They all have a gimmick at their core, but they don't all manage to make this gimmick interesting. The collection has two stories though that I love, and it was 100% worth getting it for those two. (Light Up The Clouds and Solidity.)

You And Whose Army? — A problem we can't relate to with a solution we can't relate to. Perhaps it's due to the extreme lack of drama. Greg Egan's writing voice is so extremely rational that it dissolves every conflict. There is no anger or hate when everyone's mental model of others is reasonable and generous. OR! Perhaps this is a metaphor. Is sharing memories through a neural link all that different from sharing them by talking? I'm not sure where that takes it. I liked the ending! While the others did sciences and stuff, Linus practiced the art of handling transplanted memories. Eat dust, bros!

This Is Not The Way Home — A technical story about technical problems driven by a big mystery that is totally not answered at the end. What happened on Earth?! I need to know! This story also shows that the extremely rational writing can kill drama even in single-person stories. My friend killed herself? My fiancé was burned to death? Stranded on the Moon to die? Taking care of a baby in a space suit? Everyone on Earth possibly dead? No tears shed about that, I'm turning a buggy into a spaceship.

Zeitgeber — Again an unrelatable problem with an undramatic solution.

Crisis Actors — This was fun, but weird. A very underrepresented perspective, as our point of view is a climate denialist terrorist. I liked how some of the mental acrobatics was presented. There will be fake blood that proves it's a hoax! There is no fake blood, which proves that they already carried it off. Clear evidence of a hoax! In the end I didn't feel like we got anywhere.

Sleep And The Soul — I love Greg Egan stories where you are in a weird world, but it takes a while to figure out what the twist is. Are we in hell? Are there demons? Is Jesus normal? Turns out people in this world don't sleep. There is action and conflict and discoveries. But discovering that sleep is not evil is actually not that dramatic for a reader from our world. I think www.smbc-comics.com/comic/2014-11-17 did it better.

After Zero — The technical part is interesting. It's a geoengineering proposal with a magnetic sunlight deflector at L1. But that's basically it. There is a bit of social commentary, but I'm not a fan. Only a crowdfunding approach works, but then it turns out crowds are dumb, but then the protagonists fight dirty and win. What does this say about democracy or anything? It is definitely not intended as irony, but the competitor in the crowdfunding is a crackpot idea that almost keeps the resources from the right project. I see geoengineering ideas in a similar light. In the story CO2 emissions are already solved with clean energy. (Handwaved.) I'd rather have read a story about how that was done.

Dream Factory — The topic of animal rights is interesting and so are the technical parts. But as a story or a commentary it didn't do it for me.

Light Up The Clouds — The best one! It's maximally Greg Egan. It's from the same cloth as Clockwork Rocket and Incandescence. It's not much connected to sleeping or souls. But it more than makes up for that with orbital mechanics! We're in a binary star system. I never considered how that makes interstellar travel more feasible. Our perspective is from a non-technological non-human civilization that barely knows about stars. The characters are somehow more lovable than the humans in the other stories. We learn a few things about their cool world and it's cool history. By the end it's time to study math, kids! We're fighting a space war. Badass.

Night Running — Pretty cool! I think it keeps your attention because the gimmick raises so many questions. You want to do experiments. And the protagonist does them for you! The gimmick is not exactly a problem we all relate to, but it's a strong parallel to the "subconscious". Another ego in our body that is basically us, but not. Now that I said it like that, it's basically Severance. But somehow that didn't occur to me at all while reading it.

Solidity — Another favorite. It grabs onto a fear we all (or just I) have in our hearts. If we don't see something, is it still there? Just like we remember? We don't even remember everything about it. It could be swapped and we would barely notice. The world falls apart along these lines, with a very strong opening scene set in a high school. The story is long and doesn't really go far from the starting point. But there is a lot of humanity tied up in this fear. Do photos help? Can we still love people? What is money? What is crime? So good. Fantastic story.

I think the ones I liked are the longest ones. Maybe I just need to be immersed long enough to start liking the characters? Or maybe a long story means there's good stuff to write about there?