Old fart present and accounted for.
I have a snapshot of me taken on my first visit to EPCOT Center in the summer of 1984 up in the old Image Works taking part in the activity where they superimposed you into a video acting like a maniac. The one I did was a Western. It's commonplace today, with Twitch streamers using greenscreen on a regular basis on their home computers, but back then, it was really special. The Rainbow Tunnel and musical spots on the floor that you talked about were also favorites. It really was "The Playground of the Future" (or seemed like it) back then. It would be great if they could yank out the DVC lounge (what a waste of space) and rebuild the Image Works with modern state-of-the-art tech-based activities, but it will never happen. Too expensive to stay ahead of the curve, I guess. That was what kind of killed Future World. To those of us lucky enough to have experienced EPCOT Center during the time before it was left to founder, it really was unlike anything else in the world. It was a wonderful dream and, for a while, pulled off everything it was created to do. Sadly, I guess it never made enough money to make it worth consistently updating over the years to keep it relevant. The powers-that-be whose corporate culture is now firmly entrenched in the company are simply focused on maximizing profit and utilizing what they consider to simply be real estate, as opposed to following a vision. It is what it is, I guess.
I have a feeling that this may be my last trip to Epcot, so I'm going to rekindle what memories I can from the very small amount of Future World that remains close to what I first experienced when I was 12. It was a good place and a magical place and I hope that, if nothing else, those folks who will only experience the new Epcot can enjoy their own version of the magic. Thanks to folks like
@marni1971 and others, we have extensive records of what once was. That makes me very happy.