Duke Nukem is the first in a series of side-scrolling platformers released in 1991 by Apogee Software. It is named after its main character, Duke Nukem, who went on to appear in a first-person shooter entitled Duke Nukem 3D in 1996. The as-yet unreleased sequel to Duke Nukem 3D, Duke Nukem Forever, has earned a unique level of infamy due to its extremely long production time, now 13 years and counting.
Game score accumulates through the collection of items Duke enjoys (some examples include footballs, Joysticks, Radios, sportsfan Flags, and the highest valued item, a 10,000 pt. balloon which rises and will eventually be unobtainable as Duke can only jump so high. The Duke Nukem franchise focuses on action-packed adventure and shooting these items even affects your score in unique ways. Shooting a leg of chicken 'cooks' it, making it plump and juicy, restoring more health. Shooting a cola can that gives an increase in Duke's health can instead yield the opportunity to collect the crumpling can for a bonus 1,000 pts. Tackling an enemy that resembles "The Energizer Bunny" and taking damage in the process earns 10,000 bonus pts. Who says it keeps going and going? Duke doesn't.
Throughout the game Duke will collect key items that can: give him multiple blaster shots (up to 4 can be fired on screen at a time, he starts with 1), allow him to jump higher, and grapple onto special ceilings. Also computer-circuit-like keys can be carried to disable forcefields Duke may encounter along the way.
The game's episodes are divided into stages (levels) which have a defined beginning and exit door. Saving is only permitted in the blue hallways between stages, where depending on your gameplay in the stage prior, you receive bonus scores. For example, one bonus is earned by destroying all the cameras in a stage that Dr. Proton uses to track Duke's progress. Others aren't as obvious or simple to earn. There are 9 types of end-stage bonus.