DannyMacValve adds 100-player support to Team Fortress 2, immediately tells people not to use it
BandaThis is begging for someone to disable respawn and make a battle royale mode that absolutely no one is asking for.
SirNukeI haven't played TF2 in years, but I'd try it. TF2 has proven to be a good platform for really weird gameplay modes.
The trick would be making sure everyone doesn't just go heavy or demo and camp, I think.