Comment by DamnInteresting

The original Shadow Warrior used the same engine as Duke3D, and when 3DRealms hired a company to build an add-on campaign for Shadow Warrior, that company reached out to me to design a level based on the popularity of my NukeCity levels. I designed the level and everything, and the add-on was completed, but it was shelved when Shadow Warrior sales underperformed. Sad.

I never got paid for that work, but the campaign is out there: Twin Dragon[1]. I built Level 11: the Fortress.

[1] https://www.moddb.com/games/shadow-warrior/downloads/twin-dr...