Why even call the game species Kzinti if they were so different?
And, err, the Ringworld is not where most Kzinti live, although there are some Kzinti there on the Map of Kzin in the great ocean. Most of the Ringworld's inhabitants are humanoids descended from the Pak, the ancestral species of humanity in the Known Space universe. There are Kzinti in important roles in Ringworld, but it is not primarily about the Kzinti (although it and its sequel are the most prominent Kzinti stories Niven wrote himself; the only other works he personally featured them in were "The Warriors" and "The Soft Weapon," although a bunch of other writers contributed to the long-running but not quite canonical Man-Kzin Wars shared-universe series).
And, err, the Ringworld is not where most Kzinti live, although there are some Kzinti there on the Map of Kzin in the great ocean. Most of the Ringworld's inhabitants are humanoids descended from the Pak, the ancestral species of humanity in the Known Space universe. There are Kzinti in important roles in Ringworld, but it is not primarily about the Kzinti (although it and its sequel are the most prominent Kzinti stories Niven wrote himself; the only other works he personally featured them in were "The Warriors" and "The Soft Weapon," although a bunch of other writers contributed to the long-running but not quite canonical Man-Kzin Wars shared-universe series).