More of a proof of concept type of thing.
90’s kids almost certainly remember Diddy Kong Racing. Aside from Mario Kart 64, it was the other racing game everybody had for the N64. And it had the benefit of both being made by Rare, and coming out later in the console’s life cycle, meaning they were able to squeeze more out of the system.
CryZENx, a.k.a. the guy that does all of those Ocarina of Time in Unreal 4 tech demos, decided to work on something else. The initial Diddy Kong Racing hub world is the result of that. It isn’t any of the tracks or anything, but you can play around in the hub world if you want. The link is in the description of the video if you’d like to tool around the hub world for nostalgia’s sake. It’s extremely unlikely to turn into anything, given how litigious Nintendo is, but it’s still pretty cool.