As an alienated teenager, I remember spending hours during high school filling the margins of my notebooks with outrageous pictures of sexy heroines, fire-breathing monsters, horrifying mutants, and post-apocalyptic landscapes. This movie plays out like a visual transcription of all the daydreams I had during that period of my life. Escapism is the name of the game—if you don't want to be there, you won't like it. Heavy Metal is still probably my favorite magazine of all time, if only because it's the one publication that can take you to more places between its covers than National Geographic.
Each issue of Heavy Metal is just like this movie—a series of tongue-in-cheek fantasy and science fiction themed comic book stories that are 'adult' in nature and not connected in any meaningful sense. It's an anthology magazine more about showcasing the wonderful art and talents of the contributors than anything else. This movie brilliantly captured the look and feel of the magazine by having a different animation studio work on each episode, thus introducing and appropriate art shift. The old animation style very much adds to the effect. I would never want to see a live-action adaptation of any Heavy Metal story, or an overly-sophisticated CGI movie.
The reviews who criticize this movie for having a weak connective story are missing the point. The point of Heavy Metal, of course, was never the story, but a celebration of the imagination and art of its contributors. There is bound to something in here for everyone. In this movie, if you don't like Harry Canyon, Den, or Captain Sternn, you only have to wait a little while before their respective stories are over. As Heavy Metal 2000 proved, a feature-length narrative with a story as thin as any of these would soon wear out its welcome. The Animatrix was about as close as we've come to having a spiritual successor to this wonderful film, and it fell short. And of course we have some adult animation these days, but almost nothing with the visual ambition of this film. This movie is a true gem. There's nothing else quite like it.