- last post: 01.01.0001 12:00 AM PDT
On the first level get the pistol from Captain Keyes and activate it by running outside. Then go to Keyes and pop him in the head. Marines will storm the room and you wont be able to kill them, for they are invincible. Easy, Normal, Heroic, or Legendary, you can't beat them. That I believe is the only unbeatable part in Halo