This is my first entry in the Ringworld universe, and I did find it enjoyable. I borrowed it as an audiobook from the library so that's why I chose to begin the series here. I have read other Niven books, and it definitely felt like this was one of his. An alien race whose contact with earth could have dire consequences for the planet and the human race, not because of the aliens' personal desire for destruction or annihilation of another race, but more because their biology and physiology has shaped their psychology so much their desire is genetic programmed. The book's climax is almost like a chess game, with little action but much manoeuvring between the main character's and their foe.