I think the thing that bothers me most about this novel is the novelist. Had Anderson actually read any of the Verne's work, he might have understood how patently ridiculous the idea of a novel based on the "real" Captain Nemo is.
Why? Well, "Nemo" is a pseudonym, for one. It comes from The Odyssey. When Odysseus blinds the Cyclops, the creature roars out a demand for the name of the man who has done this to him. The answer is "Nemo", or "No man", which is how Odysseus tricks the Cyclops into lying to his brethren. "Who did this to you?" they ask. "Nobody. Nobody did this to me."
So, Verne has his unnamed Captain adopt the name "Nemo" to show that he has separated from the world of men, and their greed and abuse. The idea that it is a true surname is absurd.
At the end of "The Mysterious Island", Verne reveals that Nemo is an expatriate Indian, which makes it even more unlikely that he would be around to befriend the boyhood version of Verne.
Of course, Verne could have made that bit up.
Tie it all to dull writing and a drab storyline and what you get is a dreary, dreary book that will make your blood boil with annoyance.