It really depends on the child. We've only been once, my oldest daughter had just turned 9, and my younger DD was almost 5. The 9yr old was scared and didn't eat. The clips didn't phase the almost 5 yr old. It scared my oldest so much that we have never been back, and she never ever wants to go there again...and now she's 17.
To me, the clips are all cheesy B movie sci fi films--we went there with my Dad--who enjoyed the clips as they were of movies that were playing at theaters when he was a teenager.