I thought it very good, no need for me to add the qualifier "for a first novel". Interesting characters I could care about; intriguing plot. It's written mostly in first-person from Arizona's perspective with some occasional third-person interludes, mostly from her mother's viewpoint. Breaking away from a first-person story like that usually annoys me. It didn't this time. Nicely done. I look forward to reading the next in the series.
I did balk at one incident in the story. Blame my SF-loving mother, who had me reading and discussing things like Isaac Asimov's
The End of Eternity by the age of ten, for instigating and encouraging my growth into a nitpicky science fiction geek

. Portal's author was kind enough to respond to my PM and address my concerns in a non-spoiler manner. Isn't it great to have active authors here at MobileRead?
Guys, don't get put off by the mention of "Romance" in the title of this thread. It's not Harlequin-style sweaty beefcake stuff. "Girl Meets Boy" is an important integral part of the story, but far from the only important part. The whole thing doesn't revolve around the romance -- in fact, the story would work fine with the romance removed (but be poorer for it; I liked how it was done).
I enjoyed it. Thank you, Imogen Rose.