Hello, UnrealSoftware!
When I played the game from the C&C series, I noticed that the sound track in it is very similar to the melody that is played when you start the game CS2D. «Frank Klepacki — 2nd Hand» — Is that really what it's called?
That's when you play that Zombies! gamemode and the round ends.
The default intro for CS2D was the same intro that plays when you start CS 1.6 (used to anyway), and then CS:Condition Zero Deleted Scenes.
Fun fact : I've found that zombies game mode has a sfx (when zombies win) same as C&C when ants win. I've found it while looking through Red Alert Windows theme sfx's.