Doom for the Super Nintendo is missing some of the things that made Doom on the PC amazing.
Basically, the Super Nintendo port of Doom is not very good. So much stuff had to be thrown out in order for Doom to work on the SNES, that it is no longer fun at times. When Doom came out on the PC in 1993, people were amazed at what Id Software had done. They had made a game that moved fast, had detailed imagery, and was just downright fun to play. It also supported multiplayer, and thousands of people enjoyed this. Well, if you liked these things from the original Doom, then you will hate doom on the Super Nintendo.
The SNES is not a very powerful console, and Doom is a powerful game. Right here, we can see how SNES Doom won't work out too well. First of all, because the Super Nintendo is not powerful enough to fill your whole TV screen with Doom, your view is a little smaller. This may not be a huge negative for some, but for others with small TVs, it is a negative. Second, the graphics have been toned down. Enemies just look bad, and the walls are not very detailed. Oh yeah, the ground and the ceiling have no detail whatsoever. Just one plain color. Third, the framerate sucks. If PC Doom runs at 30 FPS, then SNES Doom runs at 15-20 FPS. It gets really annoying, and if you are in a huge room filled with enemies, well, then the framerate goes down to about 10 FPS. Finally, and probably one of the worst flaws on SNES Doom, there is no save feature. Let's say you're pretty far on one episode, like Knee Deep in the Dead, and you die. Well, you just start back on the beginning of the level you died on. Well, let's say you turn of the Super Nintendo. If you turn it back on, you will have absolutely no record of your play, and you'll have to start the whole episode over again.
On a positive note, Doom on the Super Nintendo is one of the few ports to include the Spiderdemon and the Cyberdemon. And unlike other ports, it includes most of the levels present in PC Doom. Nowadays, SNES Doom is considered somewhat of a collectors item, and prices can go as high as $25 on eBay.
Basically what I'm try to say is 'Don't get Doom on the Super Ninteno." There are several ports that are so much better, like the Xbox Live Arcade version of Doom, or Doom on the Playstation. You can even just buy Doom on the PC from places like Steam.