Your mission in this shooting game is to enroll for an elite marksman mission deep into enemy territory, purchase upgrades and ammo to your weapons. Hold position as you defend yourself. Use YOUR MOUSE to aim and shoot (move cursor to the bottom of the screen to take cover). Press "R" KEY to reload. Use "Q" and "E" KEYS to switch weapons up and down. Press 1-7 NUMBER KEYS to explode mines or click trigger icons. Press SPACEBAR to use optical sight. Hold "X" KEY to fire grenades (M4 and XM rifles only) and press "M" KEY to switch fire mode (selective fire rifles only). Good luck!