The informal competition to run the classic game DOOM (1993) in the wildest conditions continues, and today we seem to have a contender for the victory: a Reddit user vk6_ posted in the r/itrunsdoom subreddit that he managed to create a playable version of DOOM... in a PDF file that can be run in a browser.
The project is called DoomPDF, written in C and uses Javascript, which is supported by the PDF format. The game engine is doomgeneric, a fork of the original DOOM; it requires a Chromium-based browser that uses the PDFium engine to run; the game does not work in Firefox.
The DoomPDF source code is available on GitHub. The author notes that he came up with the idea after getting acquainted with another similar project, Pdftris (Tetris in a PDF).