This movie is a dramatised documentary following the making of Melvin Van Peebles movie "Sweet Sweetback's Badasssss Song" with Mario Van Peebles playing his father. If you haven't seen that movie, just leave this for now and come back later when you have seen it. When you see this film later so you will enjoy it more.
I went to see this movie as I had seen the original on SBS TV in Australia (along with a documentary by Melvin about what led up to it) and I wanted to see how his son interpreted the role.
The original movie was interesting as it has three generations of the same family playing roles in the film. It was especially good to see the young Mario and how he reacted to his Dad making the movie and the sacrifices they had to make to follow his vision.
During the movie there are shots of the various people involved in the production talking about their experiences (played by actors.) I liked this as you normally see the original people talking about their roles and having the people in the movie doing it made it seem like they were sharing their experiences as they went along.
They did have the usual "main character materialises and argues with the director" thing, but it was only in a few scenes. One big surprise for me was one of the big Hollywood names behind the finance for the movie, who really saved the movie for Melvin at the last minute. Also watch for a funny cameo by Adam West as a gay movie investor.
Hopefully when they release this movie on DVD or screen it on TV they will show it along with the original movie so you can get the full story. A highly recommended "making of" movie.