A real classic.
GRAPHICS: 10
Although nowadays they plain suck, back in 1993 Doom's visuals were outstanding. The game took Wolfenstein 3D one step further by introducing non-perpendicular walls, varying height, full texture mapping and darkness, and the results were incredible. The game's visuals were amazing, the levels were very rich in detail, the monsters looked menacing and everything fit together. Also, it ran well on a medium-end 1993 PC.
SOUND: 9
Doom's sound was just amazing, despite becoming opaqued by new technologies as years passed by. The monsters' grunts and growls sounded really threatening, the guns packed a punch and the music fit the game well (although there were pairs of levels sharing the same song). Also, the game added a positional sound system, which added a lot to the environment (i.e. hearing a Demon's growl in the distance, or a door opening far away). Also, nearby enemies would be attracted by your gunshots.
GAMEPLAY: 10
Doom's easy to learn/hard to master gameplay made it famous. The game has simple controls and a good learning curve. The monsters had a simple AI (they just ran towards the player), but it was effective back at those times (also, they could find about the player's position by hearing his shots). The levels were well designed (although some of them had nothing to do with their names) and the game was fun overall. The gun variety was nice, and all of them were well balanced.
The Good:
¤ Great balance between visuals and performance.
¤ Excellent sound.
¤ Easy to learn, hard to master.
¤ Good gameplay.
¤ Nice AI.
The Bad:
¤ Not enough music.
¤ Some levels are badly named.