Well, you came pretty darn close. Closer than I expected since you probably haven't ever played Pathways Into Darkness. It's an old Mac-only game from Bungie and the first two levels are what inspired it (as I wrote on the song page). Basically you're a marine and your mission is to carry a small nuclear bomb deep into a maze of catacombs underneath a pyramid somewhere in Mexico to stun a "dreaming god" before it wakes up and destroys the world.

The little gap in mid-song is supposed to represent the quick break when the player ascends to "Never Stop Firing" and is then attacked by many nasty headless creatures and zombies.