Also worth noting that this sort of "The End... Or Is It?" twist would already have been a recognizable pulp adventure cliche when they were making the game. Combined with the "it was all a dream" twist before that and the full "Empire Strikes Back" gag that led up to it, there's a degree of overt silliness to the ending that people tend to set aside when trying to determine the true underlying reality of the story. But in a sense, the overt silliness is the underlying reality of it all.