I've never played any of the Nukem series, and this one doesn't make me want to, really. From what I've seen, its just gimmicky as hell...
I have, and I advise that if you want some fun and some neat effects with a classic Doom-like game, then go play Duke Nukem 3D. In my disappointment after playing the demo, I replayed the first episode of Duke Nukem 3D again (and the shareware version provides the same length itself as a demo; just episode 1; Even that was longer than DNF's demo, though mine (D3D) was full version), and you know what? I had fun, and also realized just how advanced the graphics and effects were at the time, and why the hype existed in the first place.
Duke Nukem 3D was really fun, and did many things other shooters at the time didn't, and the unfortunate case/irony is that Duke Nukem Forever became the other shooters of today (regen health, gimmicks, forced one-liners, Hollywood directing). That was just sad to bear witness to. Despite my disappointment with DNF, I still want to continue my Duke3D experience, and take on Episode 2 and 3 sometime soon. Like I said, Duke3d was a fun game, and still is. Duke Nukem Forever, not so much. Seemed too predictable, and going for realism? Duke's so unreal, he's got balls of steel; one would say literally. I mean, he could take a rocket to the nuts, and still be in one piece (and "Ready for Action"). But that's also thanks to a portable med-kit (like the regen health bar, but you got to choose when to use it. Great for a pinch, but use too much of it, and you screwed yourself in a major battle later on and you have to run across some hazards to avoid fire. Mind you, they weren't common pickups either, so you could exploit them so many times. In Episode 2 and 3 especially, they were necessary to carry. Episode 4 (Atomic/Plutonium Pak), they were a must. That was when things got difficult to out of hand levels; and you still had to strategize when to use them.). Heck, even level design was pretty well done. I had to make sure I had the right weapon or equipment before taking the plunge somewhere. Once or twice, pipebombs just ruled with their use when I knew an ambush was going to happen. Even the trip mines took some strategy to place if you knew things were going to get intense after blowing up a core or something (required to make progress in a level, and a couple troops and rocket guys spawn from nowhere; place those trips where you know they'll spawn from, but away from where you'll be working.).