I was intrigued enough by this review to watch the film; found it streaming on Kanopy (free for public library card holders in the U.S.) at https://www.kanopy.com/en/product/phase-iv. Seriously trippy.

There's also a clearer upload of the "lost ending" here (age-restricted, presumably due to brief nudity): https://www.youtube.com/watch?v=0rMqT4GD944