I very much enjoyed The Neptune Project. I wasn't expecting to jump into the action quite so quickly, but rather than following a more traditional plot structure with exposition -> rising action -> climax -> falling action/denoument, I found that Polly employed several rises and declines in action instead. The structure is actually more like the crests of waves, which is cool because this book is about the ocean, after all. Also, this format allowed for a more open ending, leading to a sequel that Polly says is already written! *cheer break* 
 While genetic mutation is no stranger to the literary world, I like Polly's use of it in such an original way. Turning kids into hybrid merpeople to give them a chance at a better future is definitely not an idea that most parents would dream about, let alone allow. Learning how each of the characters discovered their abilities and how they cope is one of my favorite parts of the novel, and it's fascinating to see how these reactions affect Nere, forcing her to reevaluate her opinion of the program. 
 Another favorite aspect is Polly's characterization. Each member of the group was so distinct and memorable. I was so moved that I broke down over each death, whether the characters were likable or not. Even the dolphins maintained fairly separate personalities, even though most remained in the background. Also, I really enjoyed how much the ocean itself became a character. The way the ocean and the things in it (sharks, jellyfish, pollution, etc) maintained this fabulously terrifying presence with each new danger had me flashing back to Finding Nemo. 
 My complaints are fairly small for The Neptune Project. As a former English major, extra punctuation really bothers me so I would have taken out some of the "proper" marks during the telepathic exchanges. I thought the use of a different font and the colons was a good idea, but those colons combined with other punctuation messed with me some. I also would have liked the characters to have been aged up a bit. The transformation process is very remniscent of puberty so it makes sense that the characters were younger teens, but sometimes the way they acted made them seem older. I'm also not crazy about all the romantic entaglements with several boys forming romantic attachments to Nere and then having the girls all dislike her for it. I would have liked the girls to be a bit closer and the guys to not all seem to fall all over Nere. However, there's still at least one more book to the series and hopefully even more so I'd love to see Polly's writing grow and strengthen. This was a fantastic debut, and I know there are only more wonderful stories waiting to be released from Polly's fathomless (see what I did there?) imagination!