I have mixed feelings about this one. It was good enough to keep me reading to the end and I'll definitely remember it and think about it for a long time, but ultimately I found it unsatisfying.

The premise - a group of people live on a dark planet with no sun. They are the descendants of two humans who were left behind there many generations ago. Everyone is waiting for Earth to come and rescue them, even now when so much time has passed that they can barely remember anything about earth. Their technology is stone-age and they live as hunters on the gradually dwindling resources of the valley they are in. Then one young man, John Redlantern, starts questioning why they should stay there, waiting for Earth, and his impatience and restlessness changes the world.

The good:
A evocative setting, a planet with no sun. A dark landscape filled with glowing, flickering, pulsing plants and animals, which works nicely for the story of people trapped by both literal darkness and by their own ignorance. I loved the idea of the trees eternally pumping glowing fluid up from the hot "underworld" creating forest filled with their rhythmic humming.

The way in which John Redlantern's restlessness and ego drives him to keep trying to push everyone around him to change things is convincing and interesting.

Some of the worldbuilding is intriguing: the inevitable results of inbreeding and how that affects the group. The way in which they turn stories about their ancestors into fables.

In places, the story of John and his companions' journey becomes epic, something that you could believe would turn into a legend.

The bad:
It's very predictable. I don't think I was surprised by any of the major plot points.

You need a huge amount of suspension of disbelief. These people just happened to find, by complete accident, a planet on which they could not only breathe the air but eat the local fauna and flora and survive? Without, it seems, any problems? The animals (as far as you can tell) are pretty much earth-like but with some additions or subtractions. Six limbs, for example (why is it that so many alien worlds have six limbed creatures?) and flat eyes, and, wait for it, GREEN blood, how original!

The same incredible luck applies to many of the other plot points. People just happen to discover things, or find things for no reason other than it works for the story.

And lastly for a book that rather self consciously deals with gender issues it is rather worryingly sexist. One of the themes is that the main characters are (for some reason that is not entirely clear) discovering new ideas for the first time. And yet every single invention and idea is made by a male character. Every action that pushes the plot forward is performed by a male character. The women and girls spend their time rolling their eyes in exasperation at how impractical these men-folk are, or being irritatingly emotional at not getting enough male attention.

The main female character, Liz Spiketree, starts off being a great, interesting, rounded person but as the story progresses she diminishes into a shadow of her former self. She becomes indistinguishable from all the other worried, near-sighted moms.
Yes, the story has some interesting things to say about gender roles but it also perpetuates most of the old lies about how men and women are.

So...mixed feelings.