Space Quest was eventually remade using Sierra's newer SCI language, which allowed the game to upgrade from its original EGA graphics to VGA. This version was released on August 20, 1991; in addition to the new VGA graphics, which were drawn in 50's B-movie style, it now featured digitized sounds. The game's interface was also changed, with text-entry being replaced by a standard icon interface which would be used by many SCI games.
The VGA remake also featured the 'taste' and 'smell' icons, which would reappear in Space Quest IV. These icons are not used to solve any puzzles; instead, they merely serve as comic fodder for the game's humor.
Source: Wikipedia, Space Quest: The Sarien Encounter , available under the CC-BY-SA License.