Gundam Neo Experience 0087: Green Divers is a short film made in 2001 for a planetarium screen (that's why the screen size is constantly changing), which has of course limited its availability over the years. Up until today, if you weren't at those planetarium shows, there was no way to see it. Among fans it's mostly known for a fanboy-bait appearance by original series protagonist Amuro Ray in a really slick-looking custom Zeta Gundam variant.
It showed up recently as an extra in a Gundam mobile game, so now anybody can watch it and all us Gundam nerds have scrambled to do so because we love the purple Zeta so much.
So it's really funny that Green Divers is just a very specific educational film. Two kids riding on a civilian space transport get caught up in a battle and have to escape to earth, from escape pods to a shuttle to atmospheric re-entry. At every step of this process, we're given the actual space science involved in great detail, often down to the math. You even get to watch the before-flight instructional video for a space lifeboat. (The character skips through at a point, "enough already!")
And at the very end, for the Gundam nerds in the audience, Amuro shows up. He isn't actually shown on screen, but his voice, the custom Zeta with the big "A" on the shoulder, and everything else about his appearance give it away. Suddenly it's Gundam, for five minutes! Amuro saves the kids, of course, talks a little bit about the future, and the camera lingers on his Gundam adoringly.
I wonder what it was like if you were just a kid on a school trip and you had to watch this. You'd probably shrug. "Oh yeah, there was a Gundam movie on that trip? I don't remember anything. Amuro was there."