Complete any level of the game.
Complete the game.
Complete every level in the game on Hard.
Complete a level without dying.
Collect all of the intel in a single level.
Collect all of the intel in the entire game.
Get full destruction on a level.
Complete a secondary objective.
Complete all secondary objectives.
Kill a flame thrower guy with a flame thrower.
Complete a level using only the machine gun.
Complete a level without firing a single shot.