I watched half of it. The jumps he makes are impossible unless he's altered the gravity or glitched it or something. He is moving faster than normally possible as well. This is not an out of the box configuration someone is just running through, this appears to be a glitched copy of the game which doesn't really count.
Yes, I was right.
For instance the game featured a mod called Bunnymod Pro "to restore the gameplay to the way it was before the anti-bhop patch back in 2001". Also an enhanced HUD aided the speedrunning. The speedgamers used many scripts including "jump spam, duck spam, 180º turn for gauss boost and precise use-key actions". There are 317 segments in the game with 249 of them under five seconds in duration. The team has even published a spreadsheet on Google Docs showing the gameplay segments and timings.
He's using mods and scripts to defeat normal game mechanics and gameplay. That's not beating the game as it is, that's modifying the game. Doesn't count imho.
Also, where is the tram ride? That's part of the game as well and completely bypassed.