Quoted from pinballfan2000:This is the video of South Park prototype pinball gameplay. Is that the SP prototype you were referring to?
Seems like production code to me--not the prototype version. Some audio calls either sounded weird or played at the wrong time...perhaps a board issue.
There's a wiki which has some information on the prototype: https://tcrf.net/Proto:South_Park_(Pinball)
One difference is when you start Mr. Mackey. In the prototype, the instructions just have plain text that says "Mr. Mackie [sic]- Fast Scoring All Switches 400K-Mkay?" In the production code (as shown at 6:10 of the video), the display effect has actual artwork and instead reads "All Switches Score 500,000".