This trick is better for the unlimited money levels. When it says that your park will be closed, immediately go to your guest list and click on the people that want to leave the park. Next, move towards the exit of your park and start clicking on people on the list of people who want to leave your park. Pick the people up and move them directly to the entrance or exit of your park. They will then leave the park. Since they do not have a grudge on your park, their hate will disappear and your park rating will increase.