I agree with Tough to be a Bug as being the scariest. We were there a couple weeks ago, and the scene where the bugs attack the audience was terrifying for younger kids! The giant spray can, Hopper yelling, the audience yelling, spiders dropping from the ceiling....I had forgotten how much was going on. This visit, there must have been at least a dozen young kids screaming, and they weren't 'happy' screams. Don't get me wrong, it's a great show, but if you're kids are nervous about it, don't force them.