Imagine if kids had the same imagination of the wonders of a hospital as they do about the wonders of Disneyland. Kids dream of going to Disney, but fear the hospital. In order to change this, I agree that the first 10 minutes need to be amazing.
The idea that you will amaze every child is absurd and impossible. Every child is an individual and has their own likes and dislikes, but most children do like some similar things.
An idea that comes to mind is have characters of the popular age appropriate shows and movies waiting for the children at the door when they arrive. A simple phone call to a parent could give you a good idea of who the child wants to see. If the child arrives and sees their favorite character going through the same treatment as them, they will feel much better about going through that treatment knowing their best buddy is with them.
A partnership with the company in charge of the show/movie may be needed to provide the costumes and avoid legal fees. Knowing that the use wouldn't be to make money, but to help children I am sure they would be willing to help.
Any nurse or other appropriate staff member could be don the costume for the time that the child is there.
As the child progresses through the treatment, so could the character and it would make the child happy to have some one else healing too.
