As the title would suggest, Duke Nukem Forever basically took forever to finish.
Duke Nukem Forever has been in development for a very long time, so nobody may ever know exactly how many hours were put into the game. Gearbox president Randy Pitchford, however, was able to take a guess on the PlayStation Blog.
“I have estimated that 3D Realms invested between 3500 and 4500 man-months of effort into the game, a lot of which has been lost to the ages,” he wrote. “Meanwhile, by the time Gearbox ships the game we’ll have put in another 2500 man-months of effort. I’ve never been involved with a project of this magnitude.”
All together, that’s a staggering 6000 man-months, which adds up to an even more astonishing one million total man-hours. To put that in perspective, Gearbox’s massive Borderlands only required between 3,500 and 4,000 total man-months worth of effort.
Source: PlayStation Blog