Unused level loading screens included with the Deathmatch patch show there was going to be a Capture the Flag mode included with the game at one time. No coding nor models show any trace of a CTF mode, so these images are likely the only remnants from it.

In the Forsaken Compound, if you turn off the path near the end of the level, you will find a secret Duke Nukem skeleton hanging from a tree. When Sam approaches it, he will say, "Dude, you've been hanging here, like, FOREVER." This is a reference to the then unreleased Duke Nukem: Forever.