Capcom's Ghosts 'n Goblins (1986) is a benchmark for difficulty. You're the knight Arthur, and a single hit strips your armor down to your boxers; a second hit kills you. Enemies swarm relentlessly from both sides.

And the final insult: beat the game and it tells you it was "a trap devised by Satan" — you must play the entire thing again, harder, to see the real ending.

It should be infuriating, and it is, but the tight controls and grim atmosphere kept us coming back to die just one more time. A masterclass in making you earn every single screen.