https://www.polygon.com/2018/9/26/17905632/doom-2-battle-royale-mod-download-update

A team of modders has ginned up a way to play Doom 2 as a battle royale-style multiplayer game. While the mod, called Doom Royale (With Cheese) is still in development, the eventual goal is to have 64 players competing to be the last marine standing.

The mod is the brainchild of Retrodex Gaming. It leverages the original, 1994 PC version of Doom 2 and loads in as an alternate WAD, the bundle of files used to hold the original game’s levels. The mod is currently in testing, played mainly against bots.