Soon after it begins, the film reveals its terrible secret: written and directed by Prince, and starring him in the lead role. Oh dear... I'm sure he had great hopes for this, but sadly the end result isn't very good at all.
A positive thing: some of the songs are great, the companion album being unfairly maligned over the years probably because of the film, and everybody seems to be having a lovely time. That said, it was clearly all filmed indoors (even the outdoor scenes), and all of the sets are laughably artificial. Of course, the acting is universally dismal too, and the script is packed with spiritual hokum.
Worth a look, if only to watch it through your fingers and then laugh afterwards.
Buy "Purple Rain" instead.