Lik Sang is wrong. I have this game and to understand it, you need to know Korean. BUT you don't neccessarily have to know korean to beat the game.
The point is, you won't understand what the hell your suppose to do next. You won't understand the choices you are given to follow different paths or storyline.
Don't misunderstand me though, its one of the best if not thee best commercial korean speaking game for the GP out there.