Wolfenstein 3D is one of the old DOS games which had a lot of following. prior to the games like castle wolfestein. There was this hype for this game, as the 3D game was pretty much mature for those times. And it was kind of addictive playing this game. It's pity that it didn't remade as is with change in graphics. These days you can play the game with DOSBOX. So here's the gameplay that you should check out as well.