The basic screen layout has not changed throughout the series. There's the first-person view dominating the screen and a status bar along the bottom. There wasn't much to change here. The designers made no changes in the input structures during the evolution of the series. I think this was a sound decision.
Flight simulators are the worst offenders here.
The Doom designers had the good sense to leave well enough alone. No matter how you move around, they always face you with the same orientation. Monster AI Another area that received little attention in the evolution of the series was the artificial intelligence that the monsters use. Their attack patterns are not too smart. I noticed a slight increase in the aggressiveness of the monsters in Doom compared with the enemies in Wolfenstein 3D, but it really wasn't much of a change.