When the game has booted, in the initial front-end menu screen, press X, Y, Left-Thumbstick, Right-Thumbstick, Left-Trigger, Right-Trigger to unlock Enemy Ai Toggle, Trooper Level & a Mission List.
Level 1 Strategy:
1. Go to the edge of the first cliff in a few seconds the truck should be bombed and a guy will be outside of the little house shoot him and another will come out after you shoot him go into the house go by the desk and pick up the health then cross the bridge there will be a guy crossing it so watch out.
2. Keep going until you can snipe either the guy in the little dug-out to your right or the guy in the tower to your left i would take the guy on the left then go into the dug-out and from there snipe the guy in the tower use you pistol for more accurate shots since you don't have a sniper rifle. after this go through to the house that has an on-ramp going up to the door get inside and there will be tons of weopons to your left pick all of them up and wait in there several guys will come in shoot them all untill it starts to clear up then exit and run straight across the path to the building inside you can make sure the coast is clear
3. As soon as it is you may continue along the path eventually there will be a truck don't worry about it just follow it when you get to the building were foley is being held shoot every one there (don't hide behind the truck or anything explosive in the game when it blows up it will kill you) when everyone is cleared out go into the building and take all the weapons inside you won't be able to pick up the ak-47 it's for foley to the right of the weapons there is a desk with a key on it take it and open the cell.
4. Go back to the bridge (have foley follow you if you don't know how go to single player basic training and find out) go to the center strut (the bigest one) plant a c-4 and get off the bridge and head back towards where you started now blow the bridge and head back there will be a couple guys but it's easy keep going until you see a red flare or check you map (hit back button) the helicopter will extract you there.
(supplied by: Devin07)
Level 1, alternate Strategy:
About first mission, dont even go to the left where the tower is. Just go to the left and kill the 2 guys that come after you. Then get your law ready and blow the bmp up, then when you get farther ahead turn right where there is a walk way up the cliff and kill the 2 guys comin after you there. There will be another enemy in the little camp ground, not exactly sure where he comes from but just watch out. Then go striaght ahead and there will be a couple of guys on the ridge in front of u, kill them. Go ahead for a few steps then turn around and an another enemy will be there, kill him then kill the others where foley is.
(supplied by: yourmom2k1)