I've wanted to read this for a long time. The worldbuilding is impressive and fulfilled my - high! - expectations. It's not only the Ringworld but also everything else. The Puppeteer planets and what is going on on Earth. I enjoyed this part of the book the most. The characters are interesting but they don't capture me and I am not rooting for them like I do in many other books. What I liked least is the plot of the book. I kept waiting and waiting and waiting ... and then it's all based on Teela's luck? I am really convinced, even though the explanation is well done. The world building is still worth 3 stars and I may yet read the next book, because I'd like to know what is going to happen to the Ringworld.