I suppose it's very naughty of me to immediately think of Groundhog Day when reading this story of a man repeating part of his life over and over again. Naughty because Groundhog Day was really not very good. "Replay" has so much more depth, the characters are given enough time to experience and grow and change. It's marketed (wrongly in my opinion) as fantasy, and some reviewers instead think (also wrongly) that it's science fiction. I suppose that they think that because the main characters' repeating lives are beyond the realms of modern experience and aren't explained, but the mechanism that lets them repeat their lives is utterly unimportant. Other writers, over a period of hundreds of years dating back to the early mediaeval period have used dreams for similar purposes: to impart knowledge and wisdom to their characters so that at the end of the dream they are changed and improved. We don't call The Dream Of The Rood science fiction, or Pearl fantasy (it's a fantasy, of course, as are all fictions, but it does not fit in the modern genre of that name), so why attempt to shoe-horn "Replay" into one of those litle boxes?
This is that rare beast - both splendid literature, beautifully written and constructed; and a great story, accessible and entertaining. You should read it.