If that's the case, then it seems we have to search even more. Now that we know there was a prototype of the 28 player attraction, add that to the few other versions (1.00, 2.00, 3.01β (probably CD Drama though?), and 3.21).
I don't think it's just "blobs in a chain" though. I could be mistaken and it's just the video quality, but I believe they were using film as background for enemies (very unlikely assumption though).
(Speaking of which, is there someone that is able to translate Scenario Version 3.01β?)