Technologically it looked very well for its time, but mostly it stand out as a game with "character" (art design, levels, weapons, sound effects, voice acting, writing).

It was so cheesy and over the top that it became masterpiece (like Tarantino / Rodriguez movies, or recent Old Spice commercials).

id soft may have had technologically superior games (Quake is about the same age and had full 3d models instead of just sprites) but they were incomparably bland compared to Duke Nukem.

Also, gameplay was really fun. There were some very inspired gameplay elements: shrink and freeze guns, laser traps, remote triggered pipe-bombs, jetpacks. I still fondly remember multiplayer Duke sessions late in the night at lab in my university.

I had a CAD class in high school that was basically Duke Nukem 101. It was awesome:)

Both. IIRC, the only alternative FPS to play was Doom 2 or Quake, which had very little character and focused on the action.

The Duke Nukem engine was (from my point of view) on par with Doom's engine, but their level design made playing the game a lot of fun. From seeing yourself in the mirror, to kicking toilets and fire hydrants, the world seemed much more alive than any other game at the time.

The game had a fun boy-ish "I'm gonna kick ass" vibe to it that isn't really seen today. Most FPS action games nowadays, while fun and entertaining, seem to take themselves too seriously. Musclebound Marcus Fenix is too brooding, and Roach too focused on terrorist plots to really portray the giddiness that was found in kicking a pig in the face with your manly boot.

Plus, it came with a level editor! Oh, the hours I wasted with BUILD.EXE...

Dude, none of the things you mentioned in the level design were possible in Doom's engine.

I think you are right. I remember Duke as technically more advance than Doom 2

I found something here: http://doom.wikia.com/wiki/Duke_Nukem_3D

"While Doom and Duke Nukem 3D feature similar technology, Duke Nukem 3D could in most respects be considered technically superior. The player can jump, crouch, and aim up or down. The rendering engine features slopes, overlapping and moving sectors, arbitrary scaling of textures and strong scripting capabilities"

Ah, chalk it up to fuzzy nostalgia. I swore that the mirrors actually were functional, and you could damage stuff that was on the sidewalk with the boot-kick. Maybe I'm mixing it up with other FPS games of the time. It's been a while.

(and chalk the reply up to poor reading comprehension. I understand what you mean now)

There is a lot of technical detail about the engine from it's creator here: http://www.advsys.net/ken/default.htm

I have to note that Ken's story is one of the things got me into programming as a kid, back when DN3D was still fresh.