For my money Duke Nukem Forever is a somewhat serviceable if uninspired PC shooter that's really only compelling to play through as a piece of nerd history. You're literally walking through George Broussard's career suicide. This game sunk 3D Realms and nearly sank the series. As you progress through Forever's campaign you can literally spot the year that the section you're playing was inspired by based off of the mechanics, puzzles or dialogue. Halo, Half-Life 2, Metroid Prime, the four step profit jokes, a Leeroy Jenkins reference...it's kind of surreal.
It's an alright looking game considering the turbulent development history but the anti-aliasing and depth of field are terrible. The entire background of the game looks like it's smeared in vaseline. The gameplay is such a mish mash, it's got too many modern conventions mixed in poorly. The whole decision to only have two guns is annoying to no end. If Duke is supposed to be a one man army, he should have enough armaments for an army. It's annoying having to constantly hunt for replacement guns. The levels are tight and cramped, there's quick time events--which make absolutely no sense on pc, none, terrible idea mashing space bar every five steps in the beginning of the game--scripted events, even if they're brief there are far too many loading screens and all of the gameplay feels kind of disjointed. Like there's this collection of ideas from all sorts of different shooters but no guiding vision of what to do with all of them. Duke is almost a caricature of himself at this point, all of the Evil Dead, Ahnuld and John Carpenter one-liners kind of fall flat. The humor doesn't bother me, it's just kind of puerile and banal.
On one hand it's cool Gearbox got this out, on the other I kind of wish they did more than simply finish what 3D Realms started. There's hope for the future I guess, Gearbox has the IP, they're got a talented group down there, there's plenty of modern tropes to mine in the genre with all of the space marine and dudebro shooters. I'd love it if Duke took the piss out of some modern series ("MARIAAAAAAAAAAAA") and movies, although there's fewer action heroes to really mock in this era. That said, I think Bulletstorm does a better job of being what Duke Nukem 3D was, it doesn't take itself too seriously and it's got some stunning design and fantastic gameplay behind all of the crassness.