I have heard that the First Person Shooter Halo game franchise was inspired by Larry Niven's Ringworld. How Ringworldy is it? Is there more to the connection between Niven's classic Ringworld and the popular space FPS game than just their Ring/Halo shapes? If so, what nods to Larry Nivens classic Ringworld book series are depicted in the Halo game franchise prior to the release of Halo 4??
This Bungie web page offers a quote from Nathan Bitner, one of Halo's early developers, which provides one answer:
It's worth noting that though Halo takes place on a ring-shaped artificial world, the story, characters and world bear no relation whatsoever to Niven's excellent Ringworld novels.
Still, we can at least look at the similarities between the Halo and Known Space universes and draw our own conclusions.
Beyond the obvious similarity of habitable large scale ring-shaped structures, there is also the backstory conflict between the Forerunners and the Flood, which is similar in flavor and resolution to the Slaver-tnuctipun conflict in Niven's Known Space universe.
The Flood parasitized sentient life. The tnuctipun were master geneticists who created life forms that were presented to the Slavers as gifts which later turned out to be weapons.
The Forerunners developed the Halo array to wipe out all sentient life in the galaxy. This would deprive the Flood parasites of new hosts and wipe them out. The Forerunners activated the weapon and vanished. Plagued by the tnuctipun bioweapons, some of which were intelligent species in their own right, the Slavers had a slave race create an amplifier for their psi-talent. The Slavers then broadcast a suicide command to the whole galaxy. Everything intelligent enough to understand the command obeyed and died, including the Slavers themselves.
In both universes this galaxy-wide extinction event wiped the slate clean, giving time and space for sentient life to evolve again over billions of years. Eventually these new beings would become spacefaring and begin to stumble over the abandoned ancient and deadly technologies of the old conflict. In the Halo universe, humans find the old Halo weapons and inadvertently unleash the Flood. In Known Space, humans and other species seek out Slaver stasis boxes and unleash many dangerous things, including dormant Slavers, tnuctipun, and the Slavers' suicide weapon.
The backstories are similar in broad strokes, but the Halo gameplay diverges wildly from anything depicted into Known Space literature. I think there is enough here to suggest Known Space influence in the setup of the Halo saga, but nothing beyond that.