The laugh is, the Watch Me Die mode (the Ultra Violence of the 64 editions) is probably the easiest “hard” mode on original hardware, purely because the technical limitations prevented lots of enemies (of any tier, not just hitscan wankers) being spawned - and space limitations prevented difficulty spikes caused by Boney Bois (Plutonia-style) or Arch-Bastards ruining your day by not being included in the game at all.
It’s still a very, very good Doom game. 64 and PlayStation Doom should be played together for the alternative Doom experience.