I was looking through the GMT files earlier (not sure if they’re the same as the ones on the workshop, since this was downloaded from the SVN in early 2014), and found three files: fun_meter_intro.mp3 (which is linked), fun_loop.mp3 (just a loop of the intro of “Girls Just Want to Have Fun”), and hell_loop.mp3 (which is spooky ambience).
I think I actually remember something like this. Didn’t it also have some GLaDOS like voice lines?
Yeah I remember the fun minigame, I actually participated in one once. When an admin initiated it, GlaDOS would tell us to “have fun or die” by doing all kinds of crazy things, like running around and spamming the chat and whatever. If the fun-o-meter went to 0, your vision would turn black and white and everyone would start to burn. If the meter reached 100, happy music would start playing, explosions would happen and everything would shine brightly.
It was removed later because it was just annoying and promoted chat spamming and trolling.