Some time ago I played one of the Quake series, (I don't know which it was) and I remember that you started in a hall. There were three ways to proceed in front of you, and each way was a different difficulty. Left was easy, center was medium and right was hard. This got me thinking about ways to make difficulty options in my games. While we cannot yet select different game levels with zones, there are some things which we can control. Those that I can think of immediately are: health, weapons and ammo, ambience, and enemy spawning.
Now granted we can't make three levels in one level space, as that would not only severely restrict the size of each, but would be a terrible waist of space and a frame rate killer to boot, so we would need to make the initial paths join up once again in short order. While the paths were separate however, they could control the players starting health and weapons, as well as things like ambience, fog, number of enemies spawned in the initial zone, and so on. These initial setting could contribute to and somewhat set the difficulty of the rest (main portion) of the level.
These are some of the options that I could think of. What else is available to us and under our control? What are your thought on this and how it can be used/enhanced?
Best.