I took my 5 year old twin to this several years ago. We had been at the water parks during the day, and when the twins got tired instead of going back to the hotel I just told them to lie down on a lawn chair and take a nap there, which they did. That night as we were waiting on Fantasmic to start one of my twin looked up at me with heavy eyes and said "Mommie, I'm sweepy (sleepy), but I don't want to sweep here." We all got such a big lauch out of that, knowing the poor kid was remembering having to sleep at the water park during the day. She is 11 now, but we still pull up that priceless line whenever she says she is tired. As for the show, as soon as it started she perked up, and both the twins really enjoyed it. Don't remember them being scared at all. Go for it, it was great.