There are opportunity costs for which ever one you choose. If you choose to go to the park instead of the movies however, you will be missing out on unique cinematic experiences that only the movie theater is able to provide.
For example, movie theaters are some of the only locations available to the public where you are able to watch the brand new releases of movies. What also makes movie theaters unique from all other places is people receive the opportunity to watch the movie on a giant screen and be the first to find out what new movies are coming out later from the previews. Finally, movie theaters are famous for their movie theater popcorn.
I hope this helped!