Hold L2 and R2 then press Right, Right, Down, Up, Left, Left.
EA formation
After unlocking the Frag Grenade weapon challenge, complete all rounds and kill every enemy until round ten. If every enemy is killed, you will go into round eleven. In this round, the soldiers move and create the shape of first an "E", then
an "A" as a reference to EA Games.
Easy way to kill helicopters
When there are annoying helicopters everywhere, one of the best ways to kill them is to be a sniper. A sniper has a laser target designator which can easily kill helicopter. Also if you are a good enough aim you can use your sniper rifle to shoot the driver!
How to stay alive longer
Alot of times you are alone doing a mission and you die fast when you can't see anyone. What you should do is try to form a group or fing a group of your own soldiers to join and you should stay in the middle. First and last always die first. always look different ways than your other members are so you have more coverage. ALWAYS ALWAYS ALWAYS enter a building with your group. They will have your back and try not to shoot them or else someone else can kill you. ( on the other team of course).