"Call of Duty 4: Modern Warfare's" two-part sniper mission is definitely a hard one to complete. It has you sneaking past enemy lines to take out a target, and then carrying a wounded teammate out to safety while a whole platoon of soldiers searches for you.

But the game becomes insanely difficult once you've made your way to the evacuation point. With nowhere to hide and a limited amount of ammunition, you have to defend yourself from the attacking army until you’re rescued. Good luck getting out of this one alive.