Duke Nukem Forever was first to be made on the Quake engine, then the Quake 2 engine, then the Unreal Engine, then the Unreal warfare engine, its six years past its release date... face it, its never coming out.
A game/software/thing that does not exist but is being matketed.
Once in a Blue-Moon-Celestial-Aligment-Full-Moon-Good-Luck-Day it may have a
1 in 1 Trilion chance of being produced.
Example: Half-Life 3