Is there any way we can ask 3DR for the original plotlines?
Anyway, here's what our pal Fred said some time ago:
The switch from Quake 1 - 2 literally happened within months, so there isn't a lot of content in the Quake 1 builds.
Quake 2 also lasted briefly, and everything you see in the 1998 trailer is literally 90% of what was done. The announcement to switch to Unreal Engine, actually happened before E3 1998.
The first Unreal builds, also consisted primarily of Unreal 1 assets. In 99 they had early versions of a few levels, and weapons done, which resulted in the 99 screenshots. Afterwards development sped up, and in late 2002, the "DNF 2001" build was at it's best, before changing to a new dynamic lighting renderer, which focused on normal maps instead (Doom 3 style).
From then on, the game completely changed, and almost everything was scrapped in small segments. All levels turned out black, as a result of implementing a fully dynamic lighting engine (Just like Doom 3, and Deus Ex 2). Assets were added, replaced, and ultimately large parts of the game was completely scrapped and redone.
The 2002 - 2009 builds ultimately makes up the version of the game you guys know today.
Yes, the Doom 3 Style Switch was definitely the nail in the coffin.
A lot of great stuff in the prev. builds. My favourite part is probably the EDF "Tower" level, which starts with the highway, and the 747 crashing.
This is also where you experience the "Save the world all by yourself" scene, before reaching the top floor, cracking a code, and getting a hologram briefing of alien tech, before an aircraft crashes into the building.
Absolutely stunning and mind-blowing back in 2001.
This weapon was never implemented in any version of the game. The weapons you see in the final version are pretty much every weapon you had in the prev. versions.
The only main difference was the Flamethrower, Laser Sniper Rifle (The weapon with a row of rings at the top), and the Machinegun (Only the last version of the game had the Ripper). Every weapon back in 2001 - 2002 had multiple firemodes, selectable in an RPG like HUD. For instance, Pipebomb's could be rotated into Sticky Grenades.
The Flamethrower could turn into a "Flamewall" mode, "Acid Spray" mode, etc.
The issue is that in order to have a good looking game using Dynamig Lighting and Shadows, you need assets with Specular and Normal maps for it to compete (Especially back in 2003).
This required all assets to be remade from scratch, which was a huge undertaking.
The Singleplayer was continous like Half-Life. There was no obvious episodes, but the game was split into Zones, using "!Z1L1_1" as a format.
Each of the 6 Zones was basically episodes. Vegas, Highway, EDF Base, Desert/Ghost Towm, Hoover Dam, Area 51.
The game had you manually drive the bike through vegas (Free Roaming), all the way to the highway, and through the desert. Extremely cool.
Multiplayer was pretty much done, and very fun indeed! With 9 dedicated Multiplayer Levels, all finalized.
The laser rifle in the final game is basically a Railgun. The rifle in the 2001-2002 version was actually a sniper rifle, with a few different features.
Don't forget that Gearbox owns Duke Nukem Forever.
The plot was roughly the same. The setting was way more "Serious". Almost to a survival horror / Half Life level, which really suited the game.
I don't know why the majority of the enemies were changed back to the original. My guess would be that it had been so long since Duke 3D, that re-using the classic enemies was a "Safer Bet"