One of the big hits for everyone was going to the devil wheel. It's one of the oldest things at Oktoberfest. It is a simple wooden disk that spins around and tries to throw the people off. Last man on the disk is the winner. The staff adds some extra problems for the participants including ropes and a swinging ball if the participants don't fall off from simply spinning.
The kids all did it yesterday. It becomes even more challenging (and fun to watch) later in the evening when the beer influenced participants try to play.
Here's a video of the boys.