Firefights as you stumble through smoke and strain to determine whether the shadow ahead of you is friend or foe are both bewildering and incredibly rewarding, and it's something all gamers should try out at least once

After the round you are stuck trying to find another game with no lag (about 1 in 3 have no lag) then invite your friends in (if there is room) only to have the room close down again after the round

(divinely) mind boggling about being able to link up different machines (at that time computers) and not only participate, but kill your friends, with ultra cool weapons and the like, in -- literally -- a universe outside our own

The explosions, gunfire, screaming from mortally wounded friends and foes, chaotic commands being shouted by soldiers in a state of panic.