I was watching one of the interviews recently and they mentioned the classic objective running idea from ET/ET:QW, where you take objective X from point A to point B.
My thought was that this task is usually (always?) given to the attacking side on a given map, i.e. GDF on Island or Outskirts.
But what if you gave that task to the defending side?
Say you had security trying to track down a dirty bomb the resistance were hiding, so security attack for the first two objectives, getting ever closer to the bomb hiding place by blowing up doors and maybe guiding a defusal robot or whatnot. However, when it gets to objective 3 the resistance team essentially goes “Oh shit, we need to get this thing out of here before the security take it from us”. So the resistance team gets an objective to run the bomb from its original location, to a new “safe” one, while the security try to intercept it. If it does get intercepted then the bomb is returned to its previous location and the defusal bot gets on with defusing it, preferably rather slowly with a big progress bar somewhere :p. If the resistance get it out though, they can win the map. For stopwatch this gets a little complicated of course, but I imagine that a runner win for resistance could add xx time, or even go onto another objective which security must attack, thus delaying the win for security.
The main idea behind it would be to shift that traditional paradigm of “One side attacks, one side defends” and mix it up mid-game, so the defending side is now fleeing with the bomb and covering their own arses while the attacking side has to try and intercept them as best they can with ambushes and last-stand defences.
It provides what would be a substantially different mission to the rest just because you have to make this sudden shift from stationary defence to running the objective as hard as you can as resistance, while the attackers need to move from a slow push forwards to tracking down a running carrier.
Obviously the level will need to be designed around it; security will need to have respawn points that can intercept the runner and it obviously needs to be balanced both ways.
It may run the risk of getting over-complicated, but I still think its an interesting idea for an objective/level.