THRILL-CRAZED SPACE KIDS BLASTING THE FLESH OFF HUMANS!
A young alien falls for a pretty teenage Earth girl and they team up to try to stop the plans of his invading cohorts, who intend to use Earth as a food-breeding ground for giant lobsters from their planet.
I really hope this includes multiple rants from older characters along the lines of:
"These kids, with their rock n roll music and their root beer floats and their small gramophone discs and their fluffy hair and their skirts above the knees... They must be stopped!"