Mission 2: Operation Cobra
Difficulty: Any
As you progress through the mission, you'll secure a field with an AA (Anit-Aircraft) Gun. Once you get on this, you'll need to take out all 20 enemy planes without missing any of them.
This goal is pretty easy, and the pattern of the planes is always the same, so just make sure you're leading your shots and that the planes are getting destroyed.
If at any point you miss a plane, immediately pause the game and choose
Last Checkpoint.