something that cant happen is what happened to teh Cyberdemon . . . you cant kill it with your own weapons (lol, at teh old DOOMs, it was always nice to spend your full ammo at the cyberdemon just to keep a long fight, and to do that with all other demons arround, making it even harder) but at DOOM 3, its so easy to kill the Cyberdemon and what makes it boring is that you can kill it just with the soul cube . . . I, as most of the people I know that play DOOM, loved to kill the cyberdemon on a good fight . . . the way it is at DOOM 3, is even unfair for the poor Cyberdemon and the expected great battle o the game was turned to just another demon to be killed. I`d love to see the Cyberdemon, again, but one thats worth to be killed, by any weapon I have.
something that could be done, also, is to make the marine able to grab at the back of a demon (a large one) and shot at the face of the other demons, or to kill the demon with headshot(s) while the demon try to kill the marine by crushing him at the wall (this would make the player to chose better the situation and demon he`s going to grab, and would reduce the time he`s going to be able to remain there)
Many can remember the massive load of monsters you had to face playing the old DOOMs . . . thats one of the greatest lack at DOOM 3, when thats a lot of demons, thats some 5 or 6, or some 8 little things u kill with one pistol shot. More adrenaline, more demons, more action. (sure, the most real it gets, the harder its to have more enemies and more action at the same time, but, thats something that still make the old DOOMs good enough to be played even nowadays