Yet another one of the few games I played with my father.
I remember the setting being based on Cornwall's Burgh Island, as at one point Poirot had to venture onto the mainland to purchase some items in the local (old fashioned) shop, which required a ride on the famous Sea Tractor.
I also remember having to rescue a seagull who was coated in oil.
Unfortunately I don't remember much else, and I don't think we ever finished the game, hence I'd like to see it on GOG so that I might finally complete it, however many decades later.