A survey of sorts. And I'm not talking about scripted chase sequences or any such nonsense. When is the last time in recent gaming have you found yourself running away from a killable enemy because you were unable to kill it due to not having the means to (e.g. out of ammo) or simply because it was too difficult?
There's this section in Dead Space 2 where the enemies spawn infinitely and you have to run down a few floors before you finally have to face a Brute in the bottom. I used stasis and ran like hell during my hardcore mode run through.