It took 30 years, but a speedrunner's finished Doom 2's opening level in an unbelievable 4.97 seconds

pcgamer.com:

Speedrunner 4shockblast recently broke a record that had stood for many years on Doom 2's opening map, Entryway. Their new world record run is a masterclass in eking every possible advantage out of the map and the various speedrunning tricks Doom 2 players have discovered over the years. It's not just a new record: it's a testament to how the speedrunning community pushes one another on to previously unimaginable feats.

That may seem like a bit much, but just you wait. 4shockwave's run can be seen above, and the first thing you'll notice is that it's over almost as soon as it begins. This run of Entryway is the first-ever sub-5 second run, clocking in at 04.97 seconds, which includes all of the level's monsters and is being run on Ultraviolence (it goes down as a Pacifist run, mainly because there's no time to blow anything away).

The bar-setting record for Entryway had been set in 1998 (!) by one Thomas Pilger, a legendary figure in the early Doom scene and holder of countless records in the game.  Entryway's simplicity, a twisting corridor filled with monsters leading to a more open room with an exit door, saw Pilger set a time of 5 seconds that players assumed would be hard to substantially improve on.

In some ways they were right: Pilger's run wasn't as optimised as it perhaps could've been, but the level is so short that the opportunities to save time seem few and far between. The Finnish Doom legend Ocelot would be the first to improve on techniques for the run in 2001 (which says everything: three years in this community is a lifetime), managing a time of 05.26 thanks to the incorporation of strafing movement (increasing Doom guy's momentum) and clever use of gunshots to «guide» monsters where he wanted them to go.

One thing Ocelot didn't do was use a technique called «sr50», which is explained and showcased in great depth in Karl Jobst's excellent video on 4shockblast's achievement. Sr50 can be essentially thought of as super-strafing: a technique that