I saw it when it came out and I was in highschool (as we are similar age). I liked it very much at the time since it had lots of music I was listening to. (What these days is called Classic Rock and then was just called Rock.) I didn't specifically remember anything from UmmaGumma but it seemed plausible, given the rest of the music. Alas google informs me that nothing from UmmaGumma was on it. No Pink Floyd even. The music in it runs more to stadium rock (Journey, Blue Oyster Cult, Cheap Trick) than to prog rock.
At the time it came out I was a regular reader of the Heavy Metal comic. I was in its demographic of teenage nerd (although not in its demographic of male, since I was a girl nerd) and thought it was just the coolest comic ever. Anime hadn't been invented yet and Maus was yet to be written. I wouldn't have been ready for Maus anyway at that age. So I was a huge fan and dove right in to the movie.
I loved the movie. It was just like the comic only with music! And by no great coincidence, with the same music on my stereo whenever I was reading the latest issue.
In middle age I've sometimes gone back to visit the things I loved back then. The music of Pink Floyd and the Lord of the Rings trilogy are just as good as I remembered them. Heavy Metal, alas, is not. What was so enthralling to me then just looks bombastic and silly now. I saw some excerpts on Youtube and ....meh. It did not hold up over time.