For me this is one of the worst amusement park in Germany. If it wasn't for the kids I'd never come…read morehere. For what you get its quite expensive, 2 adults, 2 children will set you back around € 120-140 depending on how early you book the tickets. Fast pass is € 39 per person which you definitely need if it's packed. Else waiting time for the rides easily gets to 60 minutes.
The rides in general are too old. Although they add new ones every now and then, they keep some from 20 years ago. In addition they're not exciting enough anymore for today's standards.
The there those antique arcade games in the Wild West and you even have to pay for them, crazy. In general they charge money for many additional games.
They have a good action stunt show but it shows only twice a day, ridiculous.
The fast food here is bad and expensive, 3 x Pommes and 3 Softdrinks set you back € 20.
There are no better choices in this area so a lot of people still come here.
The next one would be the Phantasialand near Cologne.