versions of their entire catalogue in the space of 18 months, "with so many 8 bit computers on the markets and the introduction of Macs, and Atari STs, developing for cross platform versions of a game was becoming prohibitive in cost back in the late 1980s / early 1990s. Level 9 were able to hold their own as a small developer because they were able to optimise cross platform production of their games". The first game to use this system was Colossal Adventure in early 1982, a faithful conversion of Adventure by Will Crowther and Don Woods, but with 70 extra locations to the end game to fulfill Level 9's preexisting claim in advertisements of "over 200" locations; a remarkable achievement given that Gordon Letwin's port of Adventure to the TRS-80 required a disk drive. That year the company produced two sequels, Adventure Quest and Dungeon Adventure, both of which featured the Demon Lord Agaliarept. The three titles became known as the Middle-earth trilogy, with a reference in the instructions to Dungeon Adventure to the city of Minas Tirith, which features in J. R. R. Tolkien's The Lord of the Rings. When enhanced versions of the three games were published by Rainbird Software, the reference to Middle-earth was quietly deleted; the series became known as Jewels of Darkness; and Minas Tirith became Valaii. In 1985 Level 9 started to develop their games for disk based systems also. Snowball was the first adventure in the Silicon Dreams trilogy, followed by Return to Eden and The Worm in Paradise. Red Moon and its sequel The Price of Magik were bundled together with Lords of Time by Mandarin Software to create yet another trilogy: Time and Magik. "Lancelot" was published by Mandarin Software, a division of Europress Software in 1988. The first person to solve the puzzle in the game won a replica of the Holy Grail, made of solid silver, encrusted with semi-precious stones (amethysts, garnets and opals), with the inside plated in 22-carat gold. List of software Extension BASIC for the Nascom (198x) rqFORTH for the BBC Micro (198x) rqFORTH toolkit for the BBC Micro (198x) Compass for the Lynx (198x) List of arcade games Fantasy (198x) Space Invasion (198x) Bomber (198x) Missile Defence (198x) List of text adventure games Colossal Adventure (1982) Adventure Quest (1982) Dungeon Adventure (1982) Snowball (1983) Lords of Time (1983) Return to Eden (1984) Emerald Isle