I have never read anything like this novel, that's for sure. As a fannish person, It rang of time loop and fork-in-the-road AU fic--a chance to explore the many roads a character can take. It's just that in this case, all those roads are explored in one book.
Being the structure whore that I am, I found the inventive series of births, deaths, and rebirths stimulating, and I know one read is not enough. However, it did feel a bit overlong, one too many loops, especially around the middle. The loop featuring the main character, Ursula, trapped in Germany in proximity to Hitler would be my vote for loop to be excised or trimmed, yet it's necessary for the character to complete the task with which the book begins (killing Hitler). I almost wish that the historical stakes were taken down a notch--I loved the exploration of both WWI and WWII and the Blitz, but do we need to incorporate that common historical what-if, "What if someone killed Hitler?"
My favorite aspect of the book involves the portrait of a family and of its female characters in particular. The character I was interested by and that I found most complex was Sylvie, Ursula's mother. Ursula is thrown in flux so much with her different lives, but there's a stability to Sylvie across loops I appreciated (other characters have this stability, and Ursula herself has it to an extent in terms of personality, but I suppose what I'm saying is that I simply liked Sylvie's prickliness best).
I thought--and am still thinking--a lot about the loop in which Ursula is raped, and it essentially ruins her life (she first has an abortion she does not choose and ends up marrying a man who shows her some kindness; he later proves to be an abusive asshole that kills her). I wonder about what that says--that rape is this thing that can't be worked through, that changes you essentially, that means you're better off dead. Ursula also questions if somehow the rape is HER fault (we're meant to shout "NO!" here), but the loop in which she instinctively pushes the (American, natch) man away when he first kisses her, resulting in no rape, somehow reinforces to me that rape IS preventable--just push that dude away, ladies.
I'm going to also go ahead and admit now that I don't understand why the book ends with the loop that it does. Must re-read and keep thinking over!
Despite the above reservations, I would absolutely recommend this book.