I really enjoyed this book a lot more than I initially expected to. Normally I like my science fiction books heavy on world building, quirky characters desired by optional. If you go into reading this book with those expectations, you are probably going to be sorely disappointed. Yes, Aelyx is an alien, but the world building around his planet and culture is introduced as little tidbits of information sprinkled throughout the story--it is definitely not the focus.
I would argue, the main focus of this book (aside from the relationship between Cara and Aelyx) is the extremes to which people will go when they are afraid of something they do not readily understand. I really wish we could have gotten an alternative perspective from one of the people in Cara's town who is not so quick to welcome the L'eihrs, but the stories we hear about third person from Cara and Aelyx are still interesting and what I would consider realistic.
I think one thing "Alienated" did well was layer issues on top of one another. The relationship, the L'eihr haters, the much larger threat to both Earth and the L'eihrs (no spoilers!)--they come at the reader one by one and play off of each other. I think this is why I read this book so quickly--there really was never a dull moment for me. Between the romance, the suspense, and the betrayal there was always something going on not only in the forefront but also in the background.
There were really only two things that bugged me about this book.
The first thing is the cover. I love it, but Aelyx is described as having tan skin and long hair that he ties back at the nape of his neck with a leather cord. Why then do we get Zac Efron? I know this isn't a big deal, but it is still frustrating.
The other thing I did not care for, without spoiling anything, are some of the very quick, illogical decisions Cara makes. She is so eager to abandon things, it just feels fake in the context of the overarching story.
If you're looking for a hard core science fiction fantasy novel akin to Star Trek, look elsewhere--this is definitely not it. The world building is very light. On the other hand, if you're looking for a lot of romance and a little bit of science fiction, you have hit the jackpot! This book was fun, fast-paced, and sweet.