Duke Nukem 3D: 20th Anniversary World Tour

When you start the game, you have access to every non-secret level in the game. To unlock this achievement easily, just play the last level of the episode and defeat the boss.

Select Single Player > New Game > Shrapnel City > Stadium then your difficulty. Then, while in this level, enter the cheat code. Turn ‘God Mode’ on and select ‘Give All.’ You will need to enter the cheat code for each cheat you want to activate.

The boss area is the only area in this level. At the start you are going up a lift and appear in the center of a football field where the Cycloid Emperor is. That’s it. Defeat it by any means and the achievement will unlock during the end cutscene.

NOTE: If playing on the “Piece of Cake” difficulty, this will be the only enemy in the level. Defeating the boss on this difficulty will also unlock “Take No Prisoners.”