We all know that Duke Nukem Forever has been in been in development for 13 years. The fact the game is going to see the light of day at all is a testament to the wills of the nine 3D Realms staff who kept working on it in secret after their employer's demise, and to the artistic sympathy of Randy Pitchford, president of Gearbox Software and one of the industry's great showmen.
But the craziest thing about Duke Nukem Forever's "development hell", as Pitchford refers to it, is that the game's age has become its unique selling point.
And make no mistake, this is a 13-year-old game. The developers have slapped some lipstick on the odd pig but the occasional modern graphical effect - like depth-of-field as you change your focus between an armoured snout in the foreground and an assault trooper further away - jars with lighting arrangements, boxy geometry, angular character models and textural detail that often lacks the definition and subtlety we came to expect after Half-Life 2 in 2004. You never feel as close to 2011 as you do to 1997, and despite the ageing technology the frame-rate of the Xbox 360 version I'm getting to spend 90 minutes playing is inconsistent.
Duke's sense of humour remains just as unreconstructed as the visuals are of their time, complete with cultural references that the kids of today won't understand ("I'm from Las Vegas and I say kill 'em all!" Five points if you correctly identified Starship Troopers), while his menagerie of alien opponents do things that the rest of the FPS genre gave up on years ago.
Assault troopers hover through the air, dodging left and right or teleporting across the screen with frustrating unpredictability. The newest trick the basic pig enemy has learned is to launch himself toward you using muscular hind legs, so that he crashes wavelike against your fumbling macho hands with the geometric precision and violence of the Fiend from Quake 1.
(Which means that, yes, they've borrowed a trick from an enemy in a game released six months after Duke Nukem 3D, and so long forgotten that even its second sequel is now a budget release available via digital download services and as a free-to-play PC browser game.)
As we noted during last year's improbable public unveiling, Forever begins with Duke being blown by the "Holsom Twins" while he plays his own game on a big-screen TV in the penthouse of his casino, The Lady-Killer.
This is where he's spent the years since he last repelled an alien invasion, living the kind of energetically hedonistic lifestyle that sounds really amazing when you're watching it in a buddy comedy, but which most of us would probably rather avoid in favour of a night in with a DVD of Starship Troopers and a takeaway.
Outside the window an alien mothership hangs over Las Vegas. The aliens arrived a little while ago, claiming to have come in peace. The President has asked Duke not to get involved while delicate negotiations are taking place.
So instead, Duke descends in his golden elevator - adorned with framed magazine covers showing him chomping on cigars, cradling pistols and sharing his unself-consciously one-dimensional thoughts on "babes" - to appear on "Damn, It's Late", a talkshow that seems to be filmed in his basement.