3 Stars.
Slumber was a fun, fascinating read which kept me enthralled from the beginning with lots of intense action, mystery, drama, romance and general fun times. That being said, I did have some issues with aspects of the book, which I'll discuss below.
Slumber is a fairy tale retelling of Sleeping Beauty mashed with dystopia, and to be perfectly frank - I loved it. The premise of this book was great, and I liked how the author wove the fairy tale aspects of the story through the wider dystopia elements. The world-building in this book was intriguing, well developed and I enjoyed reading about it. Of course, a map would have helped, because, I like maps in fantasy/dystopia worlds, but that is really nothing to complain about. I was happy with the level of information revealed about the toxic mist that killed, knocked-out or mutated the world a century before this story commences (2116, if I'm correct), but I did have one niggling question - if the mist was killing people, how were they put into the frozen sleep in the holding cells? Perhaps there was an explanation and I completely missed it, but I have a feeling this is something that is going to be revealed in the next book. Everything is dangerous in the new, future world, and it was just well thought out and presented.
Now, to the characters. Slumber revolves primarily around the two MC's - Charlotte (aka, Sleeping Beauty character) and Dash (aka, the Prince character... sort of). First to Charlotte, who we spend the bulk of the book with - I understood how Charlotte felt, suddenly waking up in a world that was so far removed from all that she had ever know, but when Dash told her that everything could kill her (and she had a few experiences of the world almost killing her), why did she smell that flower? Huh? That was one of a few cases in which I didn't understand her motive. Also, I get that she felt Dash was smoking hot, but spending 99% of your though power on thinking how hot he is and how you want to kiss him etc. etc. without much consideration for the dangerous and troubling situation she was in, I couldn't related. I'd be a little more than upset at first if I woke up in a post-apocalyptic world with everything out to kill me and most of the people hostile, my first thought wouldn't be 'Huh, this guy is hot, let's make out right now, screw that the world has fallen down around me.' I'd be more where am I? How did I get here? How can I find my family/friends now? I can't touch anything/glance at anything sideways, it'll kill me! How can I manage to survive for more than five nanoseconds? And so on, survival thoughts. As stuff settled down, yeah, of course you might start thinking 'This guy is hot' but talking about it all the time had me rolling my eyes in places.
Dash was an interesting character and suitably naughty, brooding and mysterious to fulfil his role as the 'bad boy' love interest. His protective streak was cute to read, and whilst he is a jerk a lot of the time, it also translates that he's a nice guy beneath it all.
The other characters are touched on briefly, but I actually didn't mind not finding out much else about them - Charlotte and Dash carry the story very well by themselves.
The romance, for all my complaints of Charlotte thinking about Dash All. The. Time. Is well developed and progresses at a good pace - not too fast, not too slow. Not quite my favourite of all romances - the gorgeous slow-burn, but it hits a good middle ground in this book between slow-burn and insta-love.
Slumber has a packed plot of action, action, action, and I enjoyed reading about the powers some people got from mutations caused by the mysterious mist of 100 years before and the struggles people had in surviving, finding loved ones and dealing with the fact that the majority of the population was still in the frozen sleep.
So, all in all, I would recommend Slumber if you are looking for a fun, fast-paced fairy tale dystopia mash-up, that features cool powers, action fight scenes, steamy romance and a fascinating mystery.