Duke Nukem II is the sequel to Duke Nukem I, released in 1993. This time around, the evil Rigelatins set out to enslave planet Earth and all the human race. During this attack they kidnap the eponymous hero, Duke Nukem while he is on a talk show advertising his new book: "Why I'm So Great". Duke breaks free to save the world once again.
Duke Nukem II is a side-scroller like the original, except with many new features and more interactivity. The player's goal is to proceed through the levels, taking advantage of the weapons, health items, and power-ups.
The game is very similar to the original, with improved graphics, sloped surfaces and the notable ability to fire upwards and downwards.
Duke Nukem is on foot throughout most of the game, but some levels have him inside a vehicle. The game is split into four episodes, each consisting of 8 levels. In the last level of each episode, the player faces a Rigelatin as a boss.
Weapons are found in green crates and look like round coins with one of four letters on them:
- Normal Weapon (N): A short red blast that is effective against many types of enemies. The default weapon for the game. (Ammo = Infinite)
- Laser (L): A large blue laser that passes through multiple enemies and walls (but disappears when it leaves the screen), and is slightly more powerful than the default weapon. (Ammo = 32)
- Flamethrower (F): A typical flamethrower weapon. It quickly uses ammo, which is why it has twice as much as the other weapons. When fired downwards, it can be used to propel Duke into the air. (Ammo = 64)
- Rocket Launcher (R): his weapon fires a rocket, which explodes upon impact, causing massive damage. It is the most powerful weapon in the game, and can kill nearly all enemies with one shot. (32 ammo)
The weapons and ammo are carried with Duke Nukem to the next level.
Items commonly found in Duke Nukem II include:
- Soda Can: (In red crates) Gives one health. If the player does not wish to take health, they may instead shoot it, thereby blasting into the air, and then catch it to earn 2,000 points.
- Six-Pack: (In red crates) Worth six health units. It may be shot for 10,000 points.
- Turkey: (In red crates) Moves quickly once released. This is worth one health. If it is shot before touched, it transforms into a cooked turkey, worth two health units.
- Atomic Health: (In blue crates) Worth one health unit. If the player has full health when they touch it, they earn 10,000 points.
- Glass Orbs: Depending on their color, they are good for a set number of points (Blue = 500, Red = 2,000, Green = 5,000, White = 10,000). If they are shot them, they break, and the player only receives 100 points, regardless of color. However, destroying all the orbs in the level calls for one of the secret bonuses (see below).
- Letters: (In blue crates) Big Letters which spell out the word "NUKEM" are located in every level. Collecting them in order grants 100,000 points. If all are collected in mixed order, only 10,000 points are granted.
- Crystal Ball: Hidden in many levels, it is worth 10,000 points. If it is returned to the pedestal hidden elsewhere in the level, the player receives 50,000 points and a helpful hint. The crystal ball can also be destroyed for a bonus at the end of the level.