This is also a place for other people to share thoughts about what should have been done or not in the game. I want to know what other people think about this subject.
Let's start with that image, that's in game intro and box cover:

And also this other image:

Since the start, since I started playing this game around 1997, I think some things are controversial.
Machinegun:
Me thinks that in the game, the Chaingun should have been more similar to that in the cover, because that strange machinegun in the image is very badass, as if it was a more sophisticated version of the pistol.

The game also should have kept the Photon Gun (Plasma weapon) of previous beta versions.
Like this one. Ok, Legacy have that, but should have been in the original game. When I bought the game, I saw this weapon in an image in the back cover, but it was frustrating that wasn't in the game.
To me, if something is in a game cover or intro, it should be in the gameplay too.
Flamethrower:

This also should have been in the original game. Maybe not using the same Freezer texture... Or maybe it could have been a weapon with 2 fire modes (fire and ice). THAT would be amazing.
Enforcer gun:
Duke Nukem should have been able to use the Lizman weapon. This was made in Kickass mod, but that should be in the original game.
Pistol:
The game could have a laser pistol, since there are so many Liztroops. Instead, they spawn pistol ammo. Or there should have been a laser pistol or the pistol itself could shoot laser.
Ok, this was done in some mods such as Duke Plus and Kickass, but it should be in the original.
Taser and Knee:

The Knee weapon is ok, because it allows you to kick aliens asses, but the Taser should have been kept and could use the same ammunition as that old plasma cannon.
The plasma cannon shoot an electric projectile, while the taser could be like an electric baton to immobilize the enemy for a short time.
Weapons:
The weapon list could have been like this in the original game:
0th weapon: Knee (the knee could be used through some button other than the used for primary and secondary modes). With that you could kick using any weapon!
1st weapon: Taser and Chainsaw (chainsaw similar to that of Doom);
2nd weapon: Laser pistol (that weapon from liztroops with 2 fire modes, one for single attack and the second for a charged attack);
3rd weapon: Pistol and Chaingun (the chaingun being equal to that in the cover art);
4th weapon: Shotgun (that same of the original game but with a secondary fire like in Legacy);
5th weapon: Plasma Cannon (from beta versions with those 2 fire modes);
6th weapon: RPG (with a secondary attack mode for atomic ammunition);
7th weapon: Shrinker and Expander;
8th weapon: Freezer and Flamethrower (both could be the same weapon but with 2 fire modes, one for ice and the other for flame);
9th weapon: Devastator and Minigun (the minigun could be that of Lizman or Battlelord, in that a secondary firemode could shoot mortars);
10th weapon: Pipebomb and Tripbomb (this would be a slot for strategic weapons).
Scenario and the nuclear theme:
The background image as well the bonus image suggests a post-apocalyptic environment, such as destroyed streets and buildings.
The presence of a nuclear detonation in the background should make it clear the game have nuclear explosions.
Ok, there are many explosions and some reactors in the game, but not nuclear or at least that wasn't much explored. There's only one level that explored that a bit, that is Critical Mass.
To me the game could have explored that feature more, which was unique in that epoch. Not only in terms of destruction, but also the scenario.
I mean, the levels could have a more destroyed city environment, with red skies and not that boring night city texture. The game should have more destroyed scenario and more radioactive waste.
I always thought the game could have a nuclear weapon. The RPG could have been THAT weapon, in which a secondary attack used a scarce nuclear ammunition, as happens in Shadow Warrior.
Even the belt of Duke Nukem have an atomic symbol. That aspect could have been explored in a more interesting way (as a powerup for example, not just the steroids).
So yes, I think the game should have been more radioactive and post-apocalyptic in general than actually was!
Monsters:
The monsters overall are OK, but I thought that they could have been a bit bigger and more intimidating. I'm not considering the mods here.
The Pigcop insstead of a transformed policemen, as a big brutal savage boar who would make strong meele attack, a bit taller than Duke.
The Octabrain could have been twice it's size and more intimidating, firing projectiles in 360°. Instead of biting, they could damage you using a different mental power when near them.
The Octabrain also could have been able to put those eggs, with greenslimers with them.
That beta octabrain (Jelly) could have benn kept and could focus on electrical meele attacks, using their tentacles. The hug of death...
The Enforcer is ok, but the ones from beta versions should have been kept. One firing bullets, another firing flames and the other firing plasma.
The game could have another enemy that used shotgun, maybe a bigger variant of the liztrooper?
The Commander and Drone are ok. But that drone from lameduke should have been kept. That Snake Head could also have been kept, as a weaker drone.
Both egg and greenslimer are ok too. But that spider from Duke Nukem 2 could have been kept, as an enemy that could immobilize you.
The Rotategun is ok, but that organtic should have been kept too, so the game would have an alien turret.
Those robot trooper and captain could have been kept from Lameduke, as being a robotized variation of the liztroop and lizman, maybe with different features.
The Riot Tank is ok, but that Scorpion Tank should have been kept.
The Newbeast is ok. I prefer to call it Ripperbeast.
The bosses are alright the way they are already. But they could have had a bigger HP, so more time of action.
That unused DummyDuke of 0.99 beta version could be not a boss, but rather a strong clone of Duke made by aliens. It could have been an interesting miniboss.
At last, there should have been a main alien species that created all the others, as mutants, not true native aliens, but rather alien creations.
Or maybe another main alien villain (could be a Rigelatin), as the Cycloid Emperor being not the alien emperor, but as an alien tank-like weapon.
Civilians:
I also think the game could have had more civilians, both stationary and moveable. I know that in the plot most people are dead, but even in a post-apocalyptic scenario there are still a lot of people around.
And also the game could have had at least more of those dancing women and clubs, because that is one of the main features of the game.
This is one of the main themes of the game that were barely explored for my taste.
Conclusion:
So, overall the game was good and have an original concept when it was released, but there are many things I still think that lacks in the original game since from the start, without mods.
I mean, the game is good, but to me it's kinda of incomplete in many aspects.
I know the computers in 1996 had much fewer memory, but the game could have been much better if it wasn't optimized to run in 486, but rather in Pentium computers with a bit more memory.
I mean, if Duke Nukem 3D was made to run in the same computers used by the developers at the time, it's likely that it would be much better.
And maybe had an even greater impact in the game industry?
Now I want to know what you guys think about this subject. In what aspects this game could have been any different?