If this book wasn't so short I definitely wouldn't have finished this. That's not because it's the worst thing ever, I just think there's like... Nothing to it. I have zero feelings about it, if that makes sense at all. 
 There was no plot. Gwen, Peter, and the lost children went on adventures but they seemed pointless. I wasn't given any reason to care about them visiting the mermaids or the Natives. 
 I didn't have any connection with the characters. Gwen was the main character but I didn't give a damn about her. Or her sister. Or the other children. Or Peter - who we were given hardly any information about, other than he's supposed to be pretty much like the stories we grew up with. Super vague. 
 What bugged me the most was the writing. Literally everything was presented to us. Every single useless detail or thought was shared with the reader. Things I didn't need to know or things I could have figured out myself. For example, it would be stated that Gwen felt a certain way and then I would be told in minute detail that this was why. Like no. I get she felt this certain way because this certain thing was happening. I can put two and two together. This also happened with every single character present. This book is less than 300 pages and so much could have been cut out from it. 
 Waste of a pretty cover and an idea that had potential.