Something phantasmagoric features wild and shifting images, colorful patterns that are continually moving and changing.
The Greek word phantasma, meaning "image," is the ancestor of phantasmagoric, a word you can use to describe anything so weird it doesn't seem real. In the 1960's, the word was linked with psychedelic drugs that created illusions. This word can definitely apply to a movie with bizarre images, quickly changing scenes, and colors and music that are disorienting. If a romantic comedy suddenly includes werewolves and killer robots, it just became phantasmagoric. Anything phantasmagoric is extremely weird.