While the game is the right one, I have to ask... Why is the installer called "setup_osiris_2.0_2265_(64bit)_(75382)"? Seems odd to call it that instead of "doom_doom_II" or something. Was there some conflict in the database that led to the renaming, or is this some project codename that made it publicly accidentally?

I guess it was a codename for this project, as it was intended to be surprise for QuakeCon.

Made me think of the Project Osiris mod....

I suppose that makes as much sense as anything else.