Oh yes. I remember first playing Quake on a 486 and not liking it, because it felt like I was moving in a heavy sluggish tank, and later playing it on a Pentium, and loving it for the agile movement. The difference was huge!
Every room with torches was max 9FPS on 320x200 on DX2 OCed to 3x50MHz, literally 50% performance over your PC. Turnig off all objects through console made torches vanished and FPS doubled.
They've literally reinvented "platformer speedrunning" to a whole different level.