Brings back memories.. Excellent gameplay, nice graphics, interesting story and a very solitary atmosphere that goes with it. I recall sitting in front of the TV (as a child) trying to beat this one - I never have, but I came damn close to it.. Pity the 8-bits didn't have the save feature, as we know it on today's PCs ;-)
BTW I had the opportunity to try the ZX Spectrum and C64 versions, but I couldn't get to like either.. ZX was "jerky" and the C64 one was too slow. THis one got the smoothness combined with the appropriate speed just right.