All platform games are puzzle games. Most are incredibly easy, hence it’s not always obvious to think of them as such. They’re like a maze with only one path that leads directly to the end, and only occasional little side passages for health packs and breakable crates. Impossible Mission is at the other end of the spectrum; it’s really hard. Ludicrously hard. Not only is it a baffling ordeal, its puzzling nature is recursive – a Russian Doll of maddening possibilities.

The sprawling underground fortress you explore is a jumble of rooms connected by a network of corridors and lifts. Each room is multi-layered, with vertical stacks of moving platforms that offer extremely limited mobility. Then there are the patrolling kill-bots that shoot electricity and move unrelentingly towards intruders such as yourself. These rooms are death traps. Yet explore them you must, for every bookshelf or computer bank could be hiding a crucial puzzle piece.

Collecting and re-arranging these pieces ultimately allows you to crack the sinister cyber-terror plans of Dr. Elvin Atombender (your malevolent host), and save the planet from global thermonuclear war. To summarise: you have to figure out how to arrange puzzle pieces that are scattered around a labyrinth filled with perilous drops and killer robots. Oh, and the entire map structure is randomised every time you start a new game. So it’s a puzzle within a puzzle within a puzzle within a puzzle. Or in layman’s terms, a total mindfuck.