Hi, David!
While the movie clips are from 50's classic scary movies, there really is nothing scary about them. They are more silly than anything. They are movies like "The Blob" and "Attack of the 50 Foot Woman." My kids always enjoy the "commercials" that are typical of old drive-ins with the dancing food and singing soft drinks!The restaurant is on the darker side (it is supposed to be nighttime at the drive-in after all!) with a star filled sky, so if your kids do not like it dark, this might not be for them. But I really think they will get a kick out of sitting in their convertible car having their meal.
On par with Sci Fi is the 50's Prime Time Cafe that will take you back to grandma's house of yester-year. Absolutely nothing scary here, and it will bring back memories of your going to your grandparent's house with its retro design and decor.
Personally, I think your kids will be fine at Sci Fi, but if you think they might enjoy something a bit more cheerful, then head to 50's Prime Time Cafe for some home cooking! Both locations get quite crowded, so
Advance Dining Reservations are highly recommended. Enjoy!