Jasper by Adam Davidson & Andrew Pollard
Text adventures have been around since 1976 when Colossal Cave was first written in Fortran. Colossal Cave has actually been translated and is also available for SUDS. Text Adventures have their own category at World Of Spectrum, which lists 1726 games of the genre available. My favourite two games were Lords Of Time and Imagination. Both games had different zones which could be travelled between and the puzzles in each zone were linked, despite each zone having a different feel. Spectrum Adventure builds on this idea.