I just watched Laputa for the first time.

(And it was a torrent which, for the first 90% of the film, had wildly inaccurate subtitles that couldn't be turned off, which finally disappeared at the end.)

It looks like Cave Story is probably some sort of Laputa fanfic, given ( Cave Story spoilers )

Also, the film itself is Nausicaa's lighter-weight twin. I had not realized that they were so similar.