Development hell is an unforgiving place. Games that become lost in its depths rarely see the light of day, and sadly for us, it's often potential classics that suffer this fate. The cancellation of a flagship title can be significant enough to condemn its home platform to the proverbial scrapheap or force a studio into liquidation, while the game-buying public is left wondering what might have been. Next month sees the launch of Duke Nukem Forever, a sequel the world had long thought lost in limbo. To mark the occasion, we opened up the vapourware vault to pay tribute to some of the games that weren't so fortunate.