This little gem of a clip is from Studio Ghibli's test pilot from 1984 for a full-length movie adaption of Little Nemo: Adventures in Slumberland, a comic strip by Winsor McCay from the early 1900's. The story follows a young boy and his adventures in surrealistic dreamscapes on his flying/walking bed. How awesome is that?
The movie was never completed despite the big names once attached to the project. Rumor is that Miyazaki didn't want to make a movie that only took place in a dream ... for some reason. The comic strip is beloved by retro comic aficionados and illustrators, and there was eventually a Japanese adaption of the comic under different artists, though that movie was soundly rejected at the box office. I think we're all a bit disappointed at the prospect of what-could-have-been. Oh, and one last thing.