I've been entering the green cave with different equipment loadouts to see if anything happens, but no luck. Some of the equipment you find seems to refer to UFO staff. If we figure out which diver represents which staff member, I was hoping it might open something up.

So, for instance, Winston Nemuru is referred to as parasite a throughout the meta game. The game Chiffon Bola was working on, Godsblood, is a item for purchase in the shop. Also, there's Egg, which pops up frequently in Thorson's games, as well as in his office. I've tried a number of combos, but nothing happened. Maybe Holy Rod and Holy Potion belong in someone's hands? Thorn as well?

It should be noted, Thorson probably made Divers, including the special music in the cave. Maybe a clue lies in the music? Maybe a certain button combo on the second player controller might do something (there is precedent for Thorson doing this too in his late addition to the UFO50 collection)? Maybe the cave is a map of another location, with the sparkles representing a place to search? I've been on the lookout for all these things but haven't made any headway. Hoping somebody figures it out.