I don't know how many of the contributing artists weren't anonymous at the time, or could be tracked down today, but if anyone knows them (or other tagged references) please feel free to add them to the tags.
The "GIGA TGL" in the copyright notice is actually the company behind the visual novel Colorful Kiss which is where the OP music is taken (and the subtitles are parodying the original lyrics).
The SWF actually has been uploaded over at post #269585 along with an entire flowchart of branches that are hidden in the flash. Though it was sent back to the moderation queue and subsequently deleted for reasons I don't understand. Good ol' Quality Check
IIRC It's archived on danbooru: post #269585 EDIT: oof, someone beat me to it. Also, as this is the "opening" for Troubled Windows, there's also an "ending" movie with Futari no Xenopittan as its song.