At first, the players starts off at the edge of a broken bridge that leads to the citadel. They actually start below the broken bridge where the dirt and debris leads them to a gap in the citadel. Upon entering, they are greeted with the moving parts of the interior structure. Some of these parts include razor trains going by, massive lifts moving through the hundreds of floors, and dropships carrying combine. As the player continues to unlock more of the citadel they stumble across the OW controlled guards (there isn't a whole area of no guards... they'll be everywhere). I won't spoil the end if this map turns out to be good.
Keep in mind that I will be puting in the massive citadel backdrops that you see in the actual game. They will be custom for the map though.
Another starting point idea is a heli/gunship pad kind of thing where the player is supposedly going to defend for a few minutes or until they can hack a console. Afterwards they will continue on through a long series of halls tunnels and (well you know what the citadel is like). I might include an elevator kind of gameplay mechanism that the players could use sort of like in the hl2 singleplayer!
Any suggestions or ideas or even comments would be appreciated. I am working on the map, I just want to know what will work and what won't. The beginning is still in early develpment