I read the book last year and thought this would be a great story for adaptation. So far they are mostly following the plot. This is quality sci-fi and true character studies. All major characters must play at least two (and frequently more) versions of themselves.
The star, Joel Edgerton, is fantastic as is his possible wife and other world gal pal Jennifer Connelly and Alice Braga respectively. The son and best friend Ryan are also superb. Another plus is that though some attempt is made to explain what is happening, it's kept at a layman's level. Naturally, what makes things so interesting is discovering what lies behind each door. These were a little too pat - frozen world, water world, nuclear world, pandemic world, future world, etc - but carried the story.
I hate that only 7 episodes were filmed but the number for a season has been dropping for years - from 23 to 18 to 12 to 10 to 8 and now 7.