This book was not as bad as it could have been, especially considering its an indie publication. (I know how snobbish that sounds.) The grammar and mechanics aren't as good as they really should be, but it isn't as bad as some.
As far as good things about the novel: Jesse, our main character's love interest, is pretty inoffensive and sweet. It's a nice change from all the emotionally abusive, he-man type characters out there. He's not all that well-developed or complex, but neither is Mira, our main character and narrator.
Mira's parents are also present in the novel, though not really as much as they should be, considering they're all visiting aliens from another planet. They do make an effort at actually being involved, though, which is nice to see. Too many authors take the lazy way out and ignore or kill off the parents.
Now, the bad: in the beginning of the novel, Ms. Reese utilizes a pretty cheap plot device. It's offensive, and dropped this rating down to one star. Mira, a supposedly super-strong alien, is nearly raped, until her love interest jumps in to save her. Because despite being a super-strong and superior alien, Mira needs a Real Man to protect her.
I don't like rape as a plot device at the best of times, and it's never addressed again by Mira, which is infuriating. She's creeped out by the stranger checking her out in her bathing suit, but the fact that her first sexual encounter was almost a rape has no impact on her. No nightmares, no flashbacks, and it certainly doesn't affect her interactions with Jesse in any way. She just moves on, because everybody knows rape isn't a real issue with actual repercussions or anything. It's just how you get a man.
The other big problem with this novel is the central villain and would-be rapist, Everett. He does things that have no rhyme or reason to them, and is little more than a cardboard cutout of a bad guy. At one point, Everett interrupts Mira's departure from Earth by kidnapping Jesse. His explanation for this is that he wants to make sure Mira returns to her home planet, except she was already leaving. To confuse matters further, Everett admits he knew this but says he had to "make sure". Make sure she does what, exactly, miss her flight home?
I wouldn't really recommend ExtraNormal, since I felt the negatives far outweighed the positives. It's also apparently supposed to be a series, which makes me wonder what cheap plot devices Ms. Reese plans on using in the second book. I doubt I'll ever find out, though, since I have no plans to continue the series.
ETA: As a quick follow-up, I wanted to mention my decision to return this for a refund. I actually do that pretty rarely, but this book is NOT worth $6, the current kindle price.