I used to use amazon customer reviews as a rough gauge of quality when purchasing ebooks. I've realized that these reviewers are consistently leading me horribly astray, and this "book" is a shining example. This is more of a pamphlet or short story, which means character development is non-existent. Maybe a half-page is spent describing characters' back-stories, and from there they go nowhere.
This story has a beginning and end, but no middle. We go from brief introductions of the characters almost immediately to the short build up to the would-be climax that never truly materializes.
The author's understanding of the subject matter (astrophysics, relativity) is mediocre, to the point where the "smartest man in the world" in the book--who is given the responsibility of explaining the numerous puzzling events to the less intelligent characters in the book (and the audience)--provides virtually zero insight as to what is actually occuring, and instead only misleads the reader and makes the story more convoluted and vague.
There is a massive difference between a compelling science fiction story with an open-to-interpretation, thought-provoking ending and an under-developed, anemic mess. This story feels a bit like a gimmick. Perhaps we should be more careful not to crown a book as a "5-star" work of art just because it has an ambiguous ending.