I hope my English don't screw up my post too much.
In King's Quest game being stuck with puzzles itself creates tension, so complex story telling tehniques aren't neccessarily needed to keep player's intrest up. Same time intro works as hook and outro creates feeling that all this adventuring lead something to that is wortwhile.
Part of story telling in King's Quest series as whole is adding layers in sequels. It also let's build characters from game to game. Heroic Graham comes heroic and lonely Graham in KQ2, heartbroken Graham in KQ3 without beeing seen untlil late in game. In KQ4 with sole power of intro Graham comes vulnerbale not in soul only as in KQ3 but also physically vulnerable to age.