Evans & Sutherland Computer Corp is finding life much more jolly now that it is out of supercomputers and into fun and games, and its latest coup is a deal with United Artists Theatre Circuit Inc to install its Virtual Glider pilots are suspended in an actual hang-gliding harness about three feet off the ground while they look through a display in which players rest their forehead against a padded head-rest while making a virtual aerial tour of the Grand Canyon or a futuristic city.