Soldiers will not shout you:
Go project IGI installed folder then goto commen\ai
backup the folder ai, There will some files like "civlian.qvm"
,"guard.qvm" like that names of enemy's copy the file
"civlian.qvm"[ctrl + c] and paste it[ctrl + v] in that same
folder, if willbe like copy of civlian.qvm then rename enemy's
files into some other names then then rename copy of civlian.qvm
into name of enemy's files like guard etc..
then start the game then enemy's willnot shout you or kill you
,If thay see you than thay will run away like civlian.
There's a secret gun in the whole game and it is on the last level
behind the crates as you kill two guys right and left with spaz 12
and open the door to the crate room and the gun is colt anaconda !