The Ocean at the End of the Lane is a part adult drama and part children horror fantasy. It started with a nearly middle aged man going over to his childhood home and then found himself at a farmhouse with a pond he remembered being called an Ocean. He remembered the time he was seven and he started reminiscing on the things he had forgotten. 
 I've been reading The Ice Palace which was frankly a perfect novel written by an author in his sixties writing a POV of 11-years old girls perfectly. I can't say this much about Neil Gaiman because his child characters seems older than they seem. I don't think Gaiman could handle innocent and naive well. I kept forgetting the narrator's age but its not a primarily inner-character driven story so I could let it slide. 
 Almost an autobiographical in nature, I do think TOatEoTL are within the same universe as Neverwhere particularly around the mythological elements within this book. Its not hard to draw parallel between Richard and George, Door and Lettie, and the parallel between the hidden city like London Below and the hidden secrets in the country. The book also employed the same Tabula Rasa much like the Neverwhere's setting, as in a person get a clean slate and finding the sense of adventure again and etc. If Hayao Miyazaki would want to work on another fantasy adaptation for his anime movies, he would find TOatEotL have the same atmospheric league as Spirited Away, Howl's Moving Castle and Tales of Earthsea. 
 I've decided for some time that Neil Gaiman's works are best in audiobooks or movie adaptations than reading his actual prose (plus Gaiman does edit it some of the chapters while reading). It does take me a while (several of his books, I mean) to handle his writing style (which tend to go on weird, flat and continuous until you listen to it) but I do think the adaptations of his work are more splendid than just reading them on paper. Plus, you will missed out on the character's intonation, the accents, the lingo, interactions etc and Gaiman does keep things out of his writings that are hard for him to put in his writings. Normally, reading this book would get a 3-star from me but the audiobooks does add more to the book. So if you want to read this book and appreciate its content more, you better get the whole audiobook and listen as Gaiman tell you his story in his own words.