the writing was fine: the characters were well fleshed out & I did empathize even with the ones I didn't like very much. The plot meanders a bit, but considering it's told from six different viewpoints and is over 500 pages long, it's actually pretty well paced.

some of the worldbuilding choices were kind of odd—instead of being set in the future, it's actually set in the recent past (the book was published in 2019, the plot starts in 2012). For it to make sense that the UK Space Agency launch an interstellar mission in 2012, the history of spaceflight is backdated to the 19th century. (Side note: I would read a whole book about that; what, were they using Analytical Engines for navigation?) Despite this radical increase in the level of technology, history apparently progressed unaffected otherwise: both world wars seem to have gone about the same, and even the 2008 financial crisis is mentioned.

there's a lot of Ideology, from the book being inescapably Christian (the author goes so far as to thank God in her acknowledgements), to the reorganization of history to give the UK a functional space program (& to make them the first people to go to Terra-Two, despite the slower Chinese mission that launched first & also the device they use to Make Ship Go Fast being Soviet technology), to Juno's very "liberal inventing communism from first principles" Damocles Document and the ensuing discussion about it, where Harry equates "everyone's basic needs being met and the abolition of private land ownership" to fascism.