Gearbox was developing a new Duke Nukem focused on the origins of Duke. The company contracted Janimation in 2008 to produce a vertical slice of their new title: Duke Nukem Begins. The vertical slice is a kind of prototype to visualize the main features of a game ahead of the entry of the game in the full production stage.
Gregor Punchatz has uploaded the video of Begins, a third-person cooperative shooter:
The game was canceled, but at least we have this video to see the general gameplay idea for the Duke’s first adventure. Right now, Embracer keeps the rights for Duke Nukem after the acquisition of Gearbox and 3D Realms.