This is a tool-assisted speedrun. For more information, see http://tasvideos.org/3799M.html. TAS originally published on 2018-10-08.
After the events of Doom II, it was thought that the demonic threat was finally put to rest. There was a lone survivor however, and in Doom 64 it is reanimating all of its fallen brethren in one final attempt at carrying out the evil plot. The player once again takes control of the Space Marine in an effort to finally rid the universe of this dark threat.
Here, the author Headshot sets the difficulty to the maximum setting and lets all hell break loose, making you wonder if the demonic forces even stood a chance to begin with. Note #1: Due to the low brightness levels in the game, a second set of brightened encodes are available.
Note #2: There are also lossless encodes and encodes at additional resolutions available in the discussion thread (http://tasvideos.org/forum/p/475580#475580).