In Killzone 3, in singleplayer, Destroy All Overlord Dropships on the Highway.
Chapter 2 “Evacuation Orders” – Broken Highway, beginning with the fight where your allies are in Exo Mechs, immediately after defeating the spider-like Helghan machine, run forwards and keep an eye on the bridge in front and above you. Dropship #1, which looks like a hovering aircraft with red lights, will appear very shortly to drop off enemy soldiers on the bridge. You can take it down with the Minigun if you brought it with you from earlier sections or pickup the rocket launcher that is next to the ammo crate and a red barrel on your left just before the bridge. If you fail, you can restart from last checkpoint which puts you back to the part where the Exo cleared a path earlier. Destroying Dropship #1 will create a new checkpoint which you can use to restart from for the later section. Moving forwards under the bridge, a structure with a bunch of soldiers is to your left, and once you take them out Dropship #2 will appear directly ahead, just before the barrier. The checkpoint created upon completing this task. Take #2 out and an ally tank will break a path through the barrier and there’s Dropship #3 and #4 immediately one behind the other, which are on the ground behind the barrier and getting ready to lift off, so quickly take them out.