Duke Nukem Forever have its share of problems, I will tell you what I think it's the biggest one, the price.
60 bucks for what doesn't look or feel like an AAA title is just a big no-no for me. I may get it when it hit the bargain bin but not before, but for this price, I demand quality, and expect to receive it.
Outside that, I agree much of what made Duke games original, the interactive scenery, the half-naked girls and the violence are all commonplace on today gaming.
What's is left is Duke charisma, which maybe would work if this was an (short) movie, but not as a game.
I still plan to play it someday, but I waited 12 years, I can hold for a couple more.