The game is set in the year 1997 (which was the "near future" at the
time of game release). Dr. Proton is a madman, determined to take over
the world
with his army of Techbots. Duke Nukem, the eponymous hero, takes upon
the task of stopping him. The first episode takes place in the
devastated city. In the second episode, Duke follows Dr. Proton to his
secret moonbase. In the third episode, Dr. Proton escapes into the
future, and Duke pursues him through time, to put a permanent end to his
mad schemes.
The
main objective of the game is to get to the exit of each level, while
destroying enemies and collecting points. It allows many objects
onscreen to be shot: obstacles, as well as enemies, can be destroyed by
gunfire. Besides points, some collectibles include health powerups, gun
powerups, and some inventory items with special abilities.
At the end of every level (with the
exception of the last level in each episode), the player can receive up
to seven 10,000 point bonuses, earned by making certain achievements in
the level, such as destroying all cameras. At least two other Apogee
titles, Duke Nukem II and Rise of the Triad, have similar end-of-level bonuses.