http://gaming.hexus.net/content/item...em=9676&page=1

a snippet -

"Well, first thing you need to know is that the difficulty levels, easy, normal, hard and Delta not only affect the AI in their accuracy and overall behaviour, but also stuff like on Delta, you lose the crosshair, so you’ll have to use the gun sights for any kind of accuracy. Further, the Korean soldiers you face at the start of the game stop talking in ‘Korenglish’, which gives you audio cues as to their intentions but start talking purely in Korean, so unless you can speak Korean you’ll have no idea what they’re shouting to each other."