Gargoyle Games

Gargoyle Games was a British software company founded in 1983 by Roy Carter and Greg Follis in order to publish their first game, "Ad Astra". They generally specialized in games for the ZX Spectrum even though the company was originally named with the intention of publishing games for Dragon computers. They also released games on their own label Faster Than Light, as well as on the Elite label.
Two of Gargoyle's releases, "Marsport" and "Heavy on the Magick" were intended to be the first in a series of games but the planned sequels were never released. "Marsport" is often considered an unofficial companion to "Tir Na Nog" and "Dun Darach" due to its similar gameplay. 
"Tir Na Nóg" and "Dun Darach" are part of the same series, with "Dun Darach" being a prequel released the following year.