Putting myself into the shoes of a gamer in '93, Doom would have blown me away. Sure, the arcades were feeling Sega's games like Virtua Racing, but somehow managing to get a 3D shooter to run at 25-30 fps purely through DOS, that will run on a home PC in '93 just amazes me. Some very sneaky tricks must have been used to get that '3D' effect working in DOS. With good sound, good level design, and just a very classic feel to it, the overall experience feels like a primitive (but still very enjoyable) form of the games we have today.
Back then, it would've really stood out. I say this without nostalgic bias, as I wasn't even alive at the time of release, but I can still see the serious jump Doom had over Wolfenstein 3D, or Pathways Into Darkness by Bungie for the Macintosh. ID Software really had the ball rolling here, with 4 player Deathmatch support, and being a key icon in popularising the fps genre, I'm going to have to hand it to them, it's hard to make a game that will still be enjoyable decades later.
For its time, I'd give it a solid 9/10.