Also there's a part in there where you have to control a RC truck and push something through a hole in the wall (no it's not a glory hole, hehehe) and that was the same as in a old game, '97, called Shaddow Warrior also from 3DRealms.
And then you've got Duke's signature male shovinist macho sayings (which is cool except when your girlfriend is in the room).
Wow, I'd completely forgotten about Shadow Warrior
