This is a proper, literal, speedrun from Zero Master. He runs, it is speedy. The 23m03s time is also relatively legit -- no glitches or tricks past the use of glides. Those involve coaxing the player's 32x32 unit hitbox through 32 unit gaps as a shortcut, or to skip collecting a few keys.
The previous record was a 23m25s run by Looper, in 2010, says Zero Master (though the linked video was posted in 2012). He also says his run is the second improvement in 10 years, pointing at an even earlier 2003 record (26m09s) set by Radek Pecka. By Zero Master's estimation, "I don't think we will have to wait that long before we see the 23 minute mark broken."
This post originally appeared on Kotaku UK, bringing you original reporting, game culture and humour with a U from the British isles.