The Warlord

The Warlord is a de-branded version of BBC Soft's Dr Who and the Warlord, which was published by Acorn User on its cover disks:

"The Warlord was originally published in a different form on cassette by BBC Soft, but in its new clothes is available to Acorn User readers who buy both this month's and next month's listings discs.

[...]

The aim of the game is to collect certain objects that your time-travelling friend Tim Trevyl will need right at the end. Which objects? Well, that's for you to discover! The first part of the adventure set in the future in Tim Trevyl's time machine; the second part is set on the night before the battle of Waterloo in Belgium."