Originally Posted by wikipedia
In an era where it was common for computer games to be written by a single person over a matter or weeks, King’s Quest I was one of the most ambitious, risky, and costly projects of its time. In addition to Williams, six full-time programmers worked for 18 months to complete the game at a cost of more than $700,000.
King's Quest I was innovative in its use of 16-color graphics on the PCjr and Tandy 1000; even CGA owners could enjoy 16-color graphics if they used a composite monitor or TV. The level of interaction with the graphics was an enormous leap over the mostly un-animated 'rooms' of previous graphical interactive fiction.
In previous games, each "room" was a static pre-drawn background and text description, and your character was usually not visible. You navigated by typing compass directions, which would instantly transport you to adjacent rooms. In King's Quest I, Sir Graham was a fully animated character walking through the CGA-rendered worlds, which were filled with other fully animated characters.
Pressing an arrow key would cause Sir Graham to begin walking in that direction. You could be southwest of a tree, walk east, and Graham would appear to walk in front of the tree. Then you could walk a few steps north, walk back west, and Graham would appear to walk behind the tree. Compass commands were no longer necessary, you moved to adjacent "rooms" by making Graham walk near an edge of the screen. Typing "OPEN DOORS" when near the castle would not cause a static predrawn image of a castle entryway with closed doors to be replaced with a static predrawn image of a castle entryway with open doors; it would cause the doors to visibly swing open.
The game relied primarily on textual input as its interface. Detractors often say that this way of interacting with games is time-consuming and frustrating, however others would argue that it requires more thought on the part of the player because it requires more than point and clicking.
