Frank O'Conner himself plays and narrates this interview/game play video that lasts over 38 minutes! He starts right at the beginning of the game. The main menu, load screen and original/updated game play. I found the video while looking through Gamespot. Click here for the entire video.
At about 20 minutes in you realize that basically you were playing a firefight when you were holding the first base and clearing all enemies until support arrived in the form of a Warthog. I had never had that thought of Halo CE in any memory before now.