A Disney movie in which the Kooky Scientist father invents a shrinking machine by which his kids are accidentally shrunk after the machine gets whacked by a baseball that came though the attic window.
It's rated pg because there is a kissing scene inside a lego out in the yard. There is also a memorable drool scene which features a remote control lawn mower.
This movie is a classic, but you can feel free to skip the ones that came after.
Starring Rick Moranis and that guy from Max Headroom and the Second Lawnmower Man movie.