Storyline: 3/5 
 Characters: 1/5 
 Writing Style: 2/5 
 World: 4/5 
 I loved the idea of the ringworld. I know the concept has been emulated elsewhere, but as far as I know, the idea originates here. Other than that idea, however, I struggled to find any wonder or suspense in the book. In fact, I had difficulty taking it seriously. I could never visualize the characters as real-life beings but only as cartoon characters or as part of a anime sequence. Additionally, I felt that something was off with the pacing, and I really didn't care about how the plot was going to resolve. 
 This book is of the far-future variety with a dose of hard science thrown in. The science is mostly connected with future discoveries and understandings of astrophysics, thus it is perhaps a misnomer to call it hard science (maybe, instead, speculative hard science). At the very least Niven has to be given credit for attempting a scientific basis for his universe. That, coupled with the object of discovery, made the book a worthwhile read. 
 A side note for those who wonder about the age appropriateness of the work: there are a lot of gratuitous sex-scenes in the book. Whenever the story slows between the main plot sequences sex is thrown in. The scenes are not exceptionally graphic but just enough that it is too explicit for a PG-13 rating. Also the role of every woman in the book is to provide sexual gratification for the male protagonist. Were it not for this component (and the technical science bits), this could have been read, understood, and appreciated by 10-12 year-olds.