Wibbling Wilf (1991)

Essentially a Pac-Man variant, the particulars of this top-down monster-avoiding maze-completing game do a good job at concealing its origins. You control Wilf (an homage to magazine editor Wilf Hey, in an unabashed bid for a good review), an innocent dumped by circumstances beyond his control into a maze inhabited by sinister Glumphs. Armed with nothing but a drippy jam sandwich, your goal is to travel around the entire game board dropping jam on the ground without being eaten by Glumphs. Take too long and they'll unleash Frank the boiled sweet, who will undo your hard work by gobbling your tasty jam splatters.