10-year-old Jimmy Neutron is no ordinary boy, he is a boy genius! After an attempt to communicate with an alien civilization fails, Jimmy tries a few other inventions of his which all have disastrous results. Deciding to disobey his parents, Jimmy sneaks out with his friends to visit the opening night of the Retroland amusement park, then winds up caught. Grounded by his parents, Jimmy wishes that parents were not around. Unbeknownst to him, his alien message makes it to its destination and an alien civilization set on his parents comes to earth and kidnaps all the adults in Jimmy's hometown After a day of fun turns sad when the town's kids miss their parents, they must all make a space voyage to find and rescue them.