There is a South Park game that was in development at around 2005 and hasn't ever been released. Not much is known about this game, I just know about these two videos of Build 656 and Build 663 linked at the bottom. Apparently someone found them in an Xbox development kit that was sold on eBay. The uploader of those 2 videos also claims he has a 3rd build, but I couldn't find a video of it. All of the builds are apparently from March 2005.

Code:
https://youtu.be/4QKaZxganvc
Code:
https://youtu.be/2404KxwjYqo
There are some more videos about this game, but I feel those 2 are the most important.

Thought it was quite interesting