Red Shift's two initial releases were designed, but not coded, by Gollop just after he left school (Time Lords and Islandia). Subsequently, Gollop learnt to program himself, designing and coding Nebula and Rebelstar Raiders for Red Shift.
Apocalypse and its two expansion packs were produced under license from Games Workshop, being based on of their board game, Apocalypse.
In 1984, a group of Harlow-based Red Shift programmers split off to form SLUG. They continued to program under license from Games Workshop (producing Spectrum versions of their board games Battlecars and Talisman.)
By 1985 Red Shift had a range of different strategy titles that appealed to fans of that genre turning to more intelligent and demanding games.
Red Shift closed after their main investor stopped supporting the team. Some staff moved on to Games Workshop.
Source: Wikipedia, "Red Shift (publisher)", available under the CC-BY-SA License.