Good Luck, Have Fun, Don’t Die ending explained by the director and writer

In the slapstick science fiction action movie Good Luck, Have Fun, Don’t Die, an alleged time traveler played by Sam Rockwell appears in a Los Angeles diner with a plan to avert the apocalypse. The world is about to end, he proclaims, if a group of volunteers can’t help him stop a child genius from creating an evil AI.