Duke Nukem Forever certainly doesn’t push the limits of a modern PC, and at medium details you’ll see very smooth performance with an $80 graphics card at 1920x1080. Increase the detail to maximum settings with anti-aliasing, and a $130 graphics card is all you need to get respectable frame rates at the same high-def resolution. When it comes to processing power, a 2.0 GHz triple-core or 2.5 GHz dual-core chip should be the realistic minimum, and this is a very reasonable requirement.
Aside from raw performance, what do we think about the game? Duke Nukem Forever has been in development for more than 14 years, but it feels as though 13 of those were spent on brainstorming sessions and concept art, while the actual programming was rushed in the last 12 months. Because of the massive wait involved, it’s almost impossible to objectively judge Duke's latest foray on its own merits.
If Duke Nukem Forever were a stand-alone indie game with no prior legacy to live up to, the community would have a much more favorable opinion of it. It offers a unique, crass lampooning of first-person shooters in general that might get a smirk out of you on multiple occasions. Folks who never played its predecessor won’t suffer from the incredibly high expectation associated with more than a decade of patience.
On the other hand, if you’ve been waiting Forever for Duke Nukem to push the limits of game world interaction like its predecessor did, you’re almost guaranteed to be let down. After 14 years maybe that’s inevitable, but it doesn’t make it any less disappointing.