For those Minnesotans, remember that Valleyfair ride called Wild Rails? Well, it's like that ride, sort of a rollercoaster, except more jerky with less dramatic drops. Primeval Whirl has the added bonus of a spinning car. So, you're spinning in a car, the track has lots of turns, then a few drops and some hard stops and starts. Basically, if you didn't have neck problems before the ride, you likely will afterwards.
But this ride always makes me the happiest of people. I'm literally laughing the entire time. You really can't beat 5 minutes of straight laughter. Just don't drag little kids on the ride, especially if they don't want to go. Because it's worse than it looks.
P.S. The whole Valleyfair thing was a total blast from the past. I wikipedia'd that shit and found out that it's completely changed from the last time I was there!