Is it a good movie?

It's barely a movie, in the classic sense of the word.

It basically serves as an extended music video, along with an excuse for Prince to goof around with his friends, pimp out his current side-projects and latest discoveries (e.g. Tevin Campbell, Ingrid Chavez), and engage in self-promotion/self-aggrandizement.

While watching it, I never got the impression that there was a script. It seemed like multiple chunks of poetry surrounded by improvisation. The direction consisted of the camera being pointed at whoever was in the current scene, and letting them talk. There were no actual actors in the film.

So, no script, no director, and no actors. If you remove all three from a movie, then what are you left with?

No. It's clear they just wanted to do a tie in movie to the album and didn't have any ideas for a movie. It plays like a messy long music video.