is their a vr game for adults only:

for sure, there will be. if you want to play games that are rated 18+ they will be orienting you. But I think most of the games in the VR park are for kids because this will be their main target market. They will be seeing what you are playing on the monitor as shown above. So if you will go to this kind of park, might as well as just enjoy it.
Actually, looking at the photos posted, the VR I think is for from teenage to adult.