There is plenty of hard scifi action here. The novel has a very strong, although sometimes sparse, plot. Niven is not one to waste words, often giving just enough to keep the story going and further his scientific speculations. For the most part, the characters are one-dimensional, with very little motivations for their actions. This is definitely a plot driven novel.
I must admit this is the first Ringworld book I have read, so the character listing and glossary came in handy. Although there is an introduction that explains the physical attributes of Ringworld, there is nothing explaining previous plotlines, which is needed to understand the first few chapters. Further into the novel it is easier to piece things together as Niven gave a little more background to the characters.
My Recommendation
If you have never read the other Ringworld books, I would not recommend reading this one first, unless you like to spend the first few chapters a bit confused. If you already know Ringworld, this is an enjoyable read.

